Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol.
The percent composition of carbon in caffeine (C8H10N4O2) is calculated by dividing the total mass of carbon in one mole of the substance by its molar mass and multiplying by 100, which equals 49.48%.
Explanation:The student has asked for the percent composition of carbon in caffeine, with the molecular formula C₈H₁₀N₄O₂. To calculate the percent composition, we first need to determine the molar mass of caffeine using the atomic masses of carbon (C), hydrogen (H), nitrogen (N), and oxygen (O). Then, we calculate the percentage by dividing the total mass of carbon in one mole of caffeine by the molar mass of caffeine and multiply by 100.
To calculate the percent composition of carbon in caffeine:
The molar mass of carbon is approximately 12.01 g/mol.Caffeine contains 8 atoms of carbon, so the total mass of carbon in each molecule of caffeine is 8 × 12.01 = 96.08 g/mol.The molar mass of caffeine (C₈H₁₀N₄O₂) is calculated by adding the molar masses of all atoms in the molecule: (8 × 12.01) + (10 × 1.01) + (4 × 14.01) + (2 × 16.00) = 194.19 g/mol.Finally, the percent composition of carbon in caffeine is (96.08 g/mol ÷ 194.19 g/mol) × 100 = 49.48%.The _______ elements tend to lose electrons and form positive ions, while the _______ elements tend to gain electrons and form negative ions.
The electropositive elements or metals elements tend to lose electrons and form positive ions, while the electronegative elements or non-metals tend to gain electrons and form negative ions.
What are metals?Metals are electropositive elements with extra electrons in their atom. Hence, they easily loss electron to achieve octet. Metals donate electrons to electron deficient non-metals forming ionic compounds.
Non -metal are located in right side of the periodic table. Except group 18 elements all the non-metals are electron deficient. Some of them such as oxygen, nitrogen, fluorine are highly electronegative and easily gain electrons from metal atoms forming ionic compounds or share electrons from other non-metals forming covalent compounds.
Therefore, metallic elements tend to lose electrons and form positive ions, while the electronegative elements or non-metals tend to gain electrons and form negative ions.
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Metals lose electrons and form positive ions, while non-metals gain electrons and form negative ions due to their atomic structure.
Explanation:The metals elements tend to lose electrons and form positive ions, while the non-metals elements tend to gain electrons and form negative ions. This is due to the atomic structure of these elements. Metals have fewer electrons in their outer shell, and thus they can easily lose them to become stable, which leads to the formation of positively charged ions. On the other hand, non-metals have more electrons in their outer shell and thus they need more electrons to become stable. As a result, they tend to receive electrons, forming negatively charged ions.
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the equation below shows the decomposition of lead nitrate. how many grams of oxygen are produced when 11.5g NO2 is formed?
2Pb(NO3)2(s) -> 2PbO(s) + 4NO2(g) + O2(g)
Answer: 2 g
Explanation: [tex]2Pb(NO_3)_2(s)\rightarrow 2PbO(s)+4NO_2(g)+O_2(g)[/tex]
As can be seen from the balanced chemical equation, 2 moles of lead nitrate produce 4 moles of nitrogen dioxide.
[tex]2\times 331.2g=662.4g[/tex] of lead nitrate produces [tex]4\times 46=184g[/tex] of nitrogen dioxide.
184 g of nitrogen dioxide will be produced by 662.4 g of lead nitrate
So 11.5 g of nitrogen dioxide will be produced by=[tex]\frac{662.4}{184}\times {11.5}=41.4 g[/tex] of lead nitrate
As can be seen from the balanced chemical equation, 2 moles of lead nitrate produce 1 mole of oxygen.
[tex]2\times 331.2g=662.4g[/tex] of lead nitrate produces 32 g of oxygen.
41.4 g of lead nitrate produces =[tex]\frac{32}{662.4}\times {41.4}=2g[/tex] of oxygen.
In the equation: MgCl2 + Na3P --> write the chemical formula for the compound that will be formed that contains Mg
3MgCl2 + 2Na3P => Mg3P2 + 6NaCl
Which of the following describes the specific copper ion in the compound, CuS?
Cupride ion
Copper (I) ion
Copper (II) ion
Cupride (I) ion
If an element in a chemical reaction loses electrons, which of the following describes what happens to that element?
A. It is combusted
B. It is reduced
C. It is rusted
D. It is oxidized
Answer : The correct option is, (D) it is oxidized.
Explanation :
On the basis of electrons, there are two types of reactions :
(1) Oxidation reaction (2) Reduction reaction
Oxidation reaction : When an element loses electrons in a chemical reaction then that element gets oxidized in the chemical reaction and its oxidation number increases.
Reduction reaction : When an element gains electrons in a chemical reaction then that element gets reduced in the chemical reaction and its oxidation number decreases.
Hence, the correct answer is (D).
Ethanol (c2h5oh) melts at -114°c. the enthalpy of fusion is 5.02 kj/mol. the specific heats of solid and liquid ethanol are 0.97 j/gk and 2.3 j/gk, respectively. how much heat (kj) is needed to convert 25.0 g of solid ethanol at -135°c to liquid ethanol at -50°c?
Melting point of ethanol = -114°c
Enthalpy of fusion = 5.02KJ/mol
Specific heat of solid ethanol = 0.97J/gk
specific heat of liquid ethanol = 2.3 j/gk.
mass of ethanol = 25.0g
moles of ethanol = mass/Molar mass = 25.0/46.07 = 0.543 moles
step 1:
solid ethanol at -135 C changing to solid ethanol at -114 C
Q1 = mass x specific heat of solid ethanol x change in Temperature
= 25.0 x 0.97 x [-114 - (-135)]
= 25.0 x 0.97 x [-114+135]
= 25.0 x 0.97 x 21
Q1 = 509.25 J
Step 2: solid ethanol at -114 C is changing to liquid ethanol at -114 C
Q2 = moles x deltaHfusion
= 0.543 x 5.02 KJ
= 2.72586 x 1000 J
Q2 = 2725.86 J
Step 3: liquid ethanol at -114 C is changing to liquid ethanol at -50 C
Q3 = mass x specific heat of liquid ethanol x change in T
= 25.0 x 2.3 x [-50 -(-114)]
= 25.0 x 2.3 x [-50+114]
= 25.0 x 2.3 x 64
Q3 = 3680J
Total heat = Q1 + Q2 + Q3
= 509.25 + 2725.86 + 3680
= 6915.11 J
Total heat = 6.915 KJ
Total heat required to convert 25.0g of solid ethanol at -135 C to liquid ethanol at -50 C is 6.9KJ.
To convert 25.0 g of solid ethanol at -135°C to liquid ethanol at -50°C, the heat required can be calculated through three main steps: heating solid ethanol to its melting point (-114°C), melting the solid ethanol to liquid form, and heating this liquid from -114°C to -50°C. With calculated heat for all three steps, the total heat required comes out to 6.913 kJ.
Explanation:The calculation for this problem is divided into three parts: heating the solid ethanol from -135°C to its melting point (-114°C), melting the solid ethanol at -114°C to liquid ethanol, and finally heating the liquid ethanol from -114°C to -50°C.
Step 1 - Heating solid ethanol to its melting point: The heat required for this can be calculated using the formula q=m*CΔT, where m is the mass of the ethanol, C is the specific heat, and ΔT is the change in temperature. The calculation is q=(25.0 g)*(0.97 J/g°C)*(-114°--135°) which equals 507.75 J, or 0.50775 kJ.
Step 2 - Melting solid ethanol to liquid ethanol: We use the given enthalpy of fusion of ethanol 5.02 kJ/mol. However, first, we need to convert the mass of ethanol to moles, which gives us 0.542 moles. Therefore, the total heat for this step will be (0.542 mol)*(5.02 kJ/mol) = 2.72 kJ.
Step 3 - Heating liquid ethanol from -114°C to -50°C: We use the same q=m*CΔT formula, replacing C with the specific heat of liquid ethanol. The calculation becomes q=(25.0 g)*(2.3 J/g°C)*(-50°--114°) which gives us 3,685 J or 3.685 kJ.
In total, the heat required is the sum of the heat from all three steps: 0.50775 kJ + 2.72 kJ + 3.685 kJ = 6.913 kJ.
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Why is a bush or tree a more accurate then a line to describe how hominds developed into modern humans
The human “family tree” may be better described as a “family bush,” within which it is impossible to connect a full chronological series of species, leading to Homo sapiens, that experts can agree upon.
How many grams of carbon monoxide are needed to react with an excess of iron (III) oxide to produce 198.5 grams of iron? Fe2O3(s) + 3CO(g) -----> 3CO2(g) + 2Fe(s) Show all work step by step please!
Fe2O3(s) + 3CO(g) -----> 3CO2(g) + 2Fe(s)
mass of iron = 198.5 g of iron
atomic mass of iron = 55.845g/mol
moles of iron = mass/Atomic mass
= 198.5g/55.845
= 3.5545 moles Fe
moles of carbon monoxide
= 3.5545 moles Fe x 3 moles CO
2 moles Fe
= 5.3317 moles CO
molar mass of CO = 12.01 + 16 = 28.01g/mol
mass of carbon monoxide reacted
= moles x molar mass
= 5.3317 x 28.01
= 149.34g
grams of carbon monoxide needed to react with an excess of iron(II)oxide to produce 198.5g of iron is 149.34g CO
Determine the value for the following reaction.
2HI(g) + 2.4 kcal → H2(g) + l2(g)
ΔH = _____
2.4 kcal
-2.4 kcal
0.0024 kcal
-0.0024 kcal
Answer:
ΔH = + 2.4 kcal
Step-by-step explanation:
2HI(g) + 2.4 kcal ⇌ H₂(g) + I₂(g)
Energy is on the left-hand side of the equation, so it is being absorbed by the system.
The thermodynamic convention is that energy going into a system is positive. Thus,
ΔH = + 2.4 kcal
Answer: 2.4 kcal
Explanation:
Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and [tex]\Delta H[/tex] for the reaction comes out to be positive.
For the given reaction:
[tex]2HI+2.4kcal\rightarrow H_2(g)+I_2(g)[/tex]
Enthalpy change is the net heat absorbed or released during a chemical reaction.
As heat is added to reactants, energy is being absorbed and thus enthalpy for the reaction will be positive and the value will be +2.4 kcal.
Is it true that Organisms need water, vitamins and minerals. But they do not need salt to function.
The following chemical equation describes the chemical reaction of hydrogen gas and oxygen gas to create water 2H2 + O2 = 2H2O Use what you know about molar relationships to explain how scientists can predict the amount of water produced if they know the amounts of hydrogen and oxygen gases they have to react.
Answer: [tex]2H_2+O_2\rightarrow 2H_2O[/tex]
The molar relationship says that every 1 mole of an element or compound weighs equal to its molecular weight.
As 1 mole of molecular hydrogen [tex]H_2[/tex] weighs 2 g.
2 moles of molecular hydrogen will weigh[tex]=\frac{2}{1}\times {2}=4g[/tex]
1 mole of molecular oxygen [tex]O_2[/tex] weighs 32 g
1 mole of water [tex] H_2O[/tex] weighs = 18g
2 moles of water [tex] H_2O[/tex] weigh=[tex]\frac{18}{1}\times {2}=36g[/tex]
As can be seen from the balanced chemical equation above, 2 moles of hydrogen react with 1 mole of oxygen to produce 2 moles of water.
Thus 4g of [tex]H_2[/tex] combines with 32 g of [tex]O_2[/tex] to give 36 moles of [tex] H_2O[/tex].
The study of chemicals and bonds is called chemistry. There are different types of elements, and these are metals and nonmetals.
The correct answer is 36 mole
What is a mole?A standard scientific unit for measuring large quantities of very small entities such as atoms, molecules, or other specified particles.
According to the question, the 2 moles of water react with the mass of water:-
[tex]\frac{18}{1}*2 = 36g[/tex].
Hence, 36 g is used to react with hydrogen and oxygen.
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Which one of these is the accepted name for the compound n2o5?
a. dinitrogen oxide
b. nitrogen pentaoxide
c. dinitrogen pentoxide
d. dinitrogen pentaoxide
The accepted name for N2O5 is dinitrogen pentoxide.
The accepted name for the compound N2O5 is dinitrogen pentoxide. It is formed by the combination of two nitrogen atoms and five oxygen atoms. The prefix 'di' indicates that there are two nitrogen atoms, and the prefix 'pento' indicates that there are five oxygen atoms.
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A 110. ml solution of 0.340 m hcl(aq) is mixed with a solution of 330. ml of 0.150 m hno3(aq). the solution is then diluted to a final volume of 1.00 l. how many moles of h+ are present in the final solution?
The total number of moles of H+ in the mixed solution is 0.079 in the mixed volume of 0.4 L. Thus the number of moles in 1 l solution is 0.197.
What is molarity?Molarity of a solution is the ratio of number of moles to the volume of solution in liters. Molarity is a temperature dependant term. This is the most common concentration term.
Here, the number of moles in 110 ml of 0.340 M HCl is calculated as follows:
number of moles = molarity × volume
= 0.340 × 0.1 l
= 0.034 moles.
Number of moles in 330 ml of 0.15 m nitric acid is 0.3 × 0.15 = 0.045.
Total number of moles in the mixed solution = 0.034 + 0.045 = 0.079. This is the number of moles in the mixed solution of 0.4 L
Hence, the number of moles in 1 liter is 0.4 × 0.079 = 0.197 moles.
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How many grams of carbon monoxide are needed to react with an excess of iron (III) oxide to produce 198.5 grams of iron? Fe2O3(s) + 3CO(g) --> 3CO2(g) + 2Fe(s)
Please SHOW WORK so I can understand the concept
The grams of carbon monoxide is 148. 68 g
calculation
Fe₂O₃(s) + 3CO (g) → 3 CO₂(g) + 2Fe (s)
Step 1: find the moles of CO
moles = mass÷ molar mass
from periodic table the molar mass of Fe =56 g/mol
moles = 198.5 g÷ 56 g/mol =3.54 moles
Step 2 : use the mole ratio to determine the moles of Co
from given equation Co: Fe is 3: 2
therefore the moles of CO = 3.54 moles x 3/2= 5.31 moles
Step 3 Find mass of Co
mass = moles × molar mass
from periodic table the molar mass of CO = 12+ 16 = 28 g/mol
= 5.31 moles × 28 g/mol = 148.68 g
The molarity (M) of an aqueous solution containing 15.6 g of sucrose, C12H22O11, in 65.5 mL of solution is:
6.96 x 10–4 M.
2.47 x 10–2 M.
0.696 M.
1.33 M.
the molecularity of C12H22O11 is = 12x12+22x1+16x11 = 342 g/mol
molarity (M) = moles / V. solution
moles = mass / 342 = 15,6/342 = 0,0456 moles
=> molarity (M) = 0,0456/0,0655 = 0,696 M
To find the molarity of a solution, convert the mass of the solute to moles, convert the volume of the solution to liters, and divide the number of moles by the volume in liters. The molarity of a solution containing 15.6 g of sucrose in 65.5 mL of solution is 0.696 M.
Explanation:The molarity (M) of a solution is calculated using the formula M = mol/L, where mol represents the number of moles of the solute and L represents the volume of the solution in liters. First, we must convert the mass of sucrose to moles. Sucrose, C12H22O11, has a molar mass of approximately 342.3 g/mol. Therefore, 15.6 g / 342.3 g/mol = 0.0456 mol. Next, we convert the volume of the solution to liters: 65.5 mL = 0.0655 L. Finally, we can calculate the molarity of the solution: M = 0.0456 mol / 0.0655 L = 0.696 M. Therefore, the correct answer is 0.696 M.
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What is the name for the Fe2+ cation?
Iron ion
Iron (II) ion
Ironide
Ferride ion
Answer:
Iron (II) ion.
Explanation:
Fe²⁺ is a cation of ion that lost 2 electrons.It can be named as iron (II) ion.Iron is the name of the metal, and (II) means that it is the cation of Fe metal that lost 2 electrons.While Iron ion may be Fe²⁺ or Fe³⁺.So, the right choice is: iron (II) ion.
Answer:
The correct answer is the option: Iron (II) ion.
Explanation:
Hello! Let's solve this!
El Hierro (Fe) has two valence numbers. Fe + 2 and Fe +3.
The +2 and +3 indicate that iron lost two or three electrons respectively.
In this case the ion is Fe + 2, this cation is called the Iron (II) ion
We conclude that the correct answer is the option: Iron (II) ion.
How has the discovery and usage of the periodic table benefited society?
Select all that apply.
It has enabled scientists to communicate chemical discoveries and results more easily.
It has increased scientists' ability to determine how cations and anions form covalent bonds.
It has increased scientists' ability to predict and discover new elements.
It has led to increased knowledge and usage of elements in technological innovations.
Final answer:
The discovery and usage of the periodic table has benefited society by enabling easy communication of chemical discoveries, predicting and discovering new elements, and driving technological innovations.
Explanation:
The discovery and usage of the periodic table has benefited society in several ways:
It has enabled scientists to communicate chemical discoveries and results more easily. The organized structure of the periodic table allows for efficient sharing of information between researchers.It has increased scientists' ability to predict and discover new elements. By identifying the patterns and trends in the periodic table, scientists can make educated guesses about the existence and properties of elements that have not yet been discovered or synthesized.It has led to increased knowledge and usage of elements in technological innovations. The periodic table provides a framework for understanding the behavior of different elements, allowing scientists to develop new materials and technologies.Kevin has 5 fish in his fish tank jasmine has 4 times as many fish as Kevin.How many fish does jasmine have?
Which statement about gases is true? A. They are made up of particles that always move very slowly. B. They are made up of particles that travel in a curved path when in motion. C. They are made up of hard spheres that vibrate quickly in stationary positions. D. They are made up of hard spheres that are in random motion.
Answer: D. They are made up of hard spheres that are in random motion.
Explanation:
A gas is a state of aggregation of matter in which, under certain conditions of temperature and pressure, its molecules interact weakly with each other, without forming molecular bonds, adopting the shape and volume of the container that contains them and tending to separate everything possible because of its high concentration of kinetic energy.
The molecules of a gas are practically free and have the ability to be distributed throughout the space in which they are contained because the gravitational forces and attraction between them are practically negligible compared to the speed at which they move. .
Therefore, gas molecules do not travel specific trajectories or vibrate in a stationary position, instead they move quickly and randomly through the entire space of the container that contains them.
The true statement about gases is that they are made up of hard spheres that are in random motion, which is option D.
Among the given options, statement D is true. Gases are composed of particles, such as atoms or molecules, that are in constant random motion. These particles move in straight lines until they collide with other particles or the walls of the container, where they undergo elastic collisions. The random motion of gas particles is responsible for their ability to fill the entire volume of the container and to exert pressure on the container walls.
Hence, the correct option is option d.
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Which explanation best compares the movement of particles in the three states of matter? A. Particles in a gas can only vibrate. In a solid, they slide against each other. In a liquid, they move freely, bouncing and bumping into each other. B. Particles in a solid can only vibrate. In a liquid, they slide against each other. In a gas, they move freely, bouncing and bumping into each other. C. Particles in a liquid can only vibrate. In a gas, they slide against each other. In a solid, they move freely, bouncing and bumping into each other. D. Particles in a solid can only vibrate. In a gas, they slide against each other. In a liquid, they move freely, bouncing and bumping into each other. E. Particles in a liquid can only vibrate. In a solid, they slide against each other. In a gas they move freely, bouncing and bumping into each other.
Answer:
e
Explanation:
**answer asap with explanation please
The table shows the nature of the reactants and products formed in a certain type of chemical reaction.
Nature of Reactants and Products
Reactants
Ionic compound + Ionic compound
Products
Ionic compound + Ionic compound
Which of the following is true about this type of chemical reaction?
It is a single replacement reaction, and all four compounds are different.
It is a double replacement reaction, and all four compounds are different.
It is a single replacement reaction, and each compound has the same set of ions.
It is a double replacement reaction, and each compound has the same set of ions.
Answer:
It is a double replacement reaction, and all four compounds are different.
Step-by-step explanation:
The equation for the reaction is
[tex]\underbrace{\hbox{ ionic compound + ionic compound}}_{\hbox{reactants}} \longrightarrow \underbrace{\hbox{ ionic compound + ionic compound}}_{\hbox{products}}[/tex]
This must be a double replacement reaction, in which the metal cations trade partners and all four compounds are different.
(A) and (C) are wrong, because single replacements involve elements in reactions of the type
element + compound ⟶ element + compound
(D) is wrong because, if each compound retained the same set of ions, there would be no reaction.
Answer:
It is a double replacement reaction, and all four compounds are different.
Explanation:
Just took the FLVS 4.03 Single and Double Replacement Reactions quiz. I got a 100.
You need to produce a buffer solution that has a pH of 5.40. You already have a solution that contains 10. mmol (millimoles) of acetic acid. How many millimoles of acetate (the conjugate base of acetic acid) will you need to add to this solution? The pKa of acetic acid is 4.74. Express your answer numerically in millimoles. View Available Hint(s)
Answer:
46. mmol
Step-by-step explanation:
The equation for the equilibrium is:
HA + H₂O ⇌ A⁻ + H₃O⁺
The solution is a buffer, so we can use the Henderson-Hasselbalch equation:
pH = pKa + log([A⁻]/[HA])
5.40 = 4.74 + log([A⁻]/(10.) Subtract 4.74 from each side
0.66 = log([A⁻]/(10.) Take the antilog of each dide
[A⁻]/10. = 10 ^0.66
[A⁻]/10. = 4.57 Multiply each side by 10.
[A⁻] = 46. mmol
You will add 46. mmol of sodium acetate.
The amount of acetate needed to add to the solution is ; 46 mmol
Given data:
pH of buffer solution = 5.4
volume of Solution ( H A ) = 10 mmol
pKa of acetic acid = 4.74
Given that the solution is a buffer solution we will apply Henderson-Hasselbalch equation:
pH = [tex]pKa + log ( [A^-] / [HA] )[/tex] -------- ( 1 )
Insert values into equation 1
[tex]5.40 = 4.74 + log([A^-]/(10 )[/tex]
0.66 = [tex]log([A^-]/(10.)[/tex] -------- ( 2 ) ( after subtracting pKa value from both side )
∴ [tex][A^-]/10. = 10^{0.66}[/tex] ----- ( 3 ) ( antilog )
Multiply both sides of equation 3 by 10
[tex][A^-] = 46 mmol[/tex].
Hence we can conclude that the amount of acetate needed to add to the solution is 46 mmol
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Complete the paragraph to describe the characteristics of silicon tetrachloride molecule (SiH4). the Lewis structure and the table of electronegativities are given.
The bond polarities of SiH4 are _____, the molecular shape is _____, and the molecule is _____.
Blank Options 1: Polar, Nonpolar
Blank Options 2: trigonal pyramidal, trigonal planar, tetrahedral, linear, bent
Blank Options 3: Polar, Nonpolar
Silicon tetrachloride (SiH4) is a covalent tetrahedral molecule with a trigonal pyramidal shape. It is nonpolar and has a low boiling point of 57 °C.
Explanation:Silicon tetrachloride (SiH4) is a covalent tetrahedral molecule with a trigonal pyramidal shape. The Lewis structure for SiH4 would show the silicon atom in the center with four chlorine atoms bonded to it. Each chlorine atom would have a lone pair of electrons, causing the molecule to have a trigonal pyramidal shape.
The electronegativity values of silicon and chlorine are 1.9 and 3.2 respectively, indicating a polar covalent bond between silicon and chlorine. However, due to the symmetry of the molecule, the dipole moments cancel each other out, resulting in a nonpolar molecule. Silicon tetrachloride is a colorless liquid with a low boiling point of 57 °C.
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Silicon tetrahydride (SiH4) is a nonpolar molecule with a tetrahedral shape due to the central silicon atom being sp³ hybridized. Even though Si-H bonds are polar, the symmetry of the molecule results in a nonpolar overall molecule.
Explanation:The bond polarities of SiH4 are Nonpolar. SiH4, or Silicon tetrahydride, is a covalent molecule with tetrahedral structure, in which Silicon (Si) forms four single bonds with four Hydrogen (H) atoms. Central Silicon atom is sp³ hybridized, which results in a Tetrahedral molecular shape. Even though the Si-H bonds are polar because of the difference in electronegativities of Si and H, the bond dipoles cancel each other because of the molecule's symmetry, making the whole molecule Nonpolar.
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2. A sample of table sugar (sucrose, C12H22O11) has a mass of 1.202 g.
a. Calculate the number of moles of C12H22O11 contained in the sample
and record in Table 1. Show your work.
b. Calculate the moles of each element in C12H22O11 and record in Table
1. Show your work.
c. Calculate the number of atoms of each type in C12H22O11 and record in
Table 1. Show your work.
Please show your work and calulation. Thanks
Answer:
a) [tex]\text{no of moles}=\frac{\text{given mass}}{\text{Molecular mass}}[/tex]
[tex]\text{no of moles of sucrose}=\frac{1.202g}{342g/mol}=0.0035moles[/tex]
b) Moles of carbon in 1 mole of sucrose [tex]C_{12}H_{22}O_{11}[/tex]= 12 moles
Moles of carbon in 0.0035 moles of sucrose [tex]C_{12}H_{22}O_{11}=\frac{12}{1}\times 0.0035=0.042moles[/tex]
Moles of hydrogen in 1 mole of sucrose [tex]C_{12}H_{22}O_{11}[/tex]= 22 moles
Moles of hydrogen in 0.0035 moles of sucrose [tex]C_{12}H_{22}O_{11}=\frac{22}{1}\times 0.0035=0.077moles[/tex]
Moles of oxygen in 1 mole of sucrose [tex]C_12H_22O_11[/tex]= 11 moles
Moles of oxygen in 0.0035 moles of sucrose [tex]C_{12}H_{22}O_{11}=\frac{11}{1}\times 0.0035=0.042moles[/tex]
c) 1 mole of carbon contains [tex]=6.023\times 10^{23}atoms[/tex]
0.042 moles of carbon contain [tex]=\frac{6.023\times 10^{23}}{1}\times 0.042=0.25\times 10^{23}atoms[/tex]
1 mole of hydrogen contains [tex]=6.023\times 10^{23}atoms[/tex]
0.077 moles of hydrogen contain [tex]=\frac{6.023\times 10^{23}}{1}\times 0.077=0.46\times 10^{23}atoms[/tex]
1 mole of oxygen contains [tex]=6.023\times 10^{23}atoms[/tex]
0.042 moles of oxygen contain [tex]=\frac{6.023\times 10^{23}}{1}\times 0.042=0.25\times 10^{23}atoms[/tex]
Why is energy required to remove an electron from an atom?
Electrons in an atom are held there by the force of attraction exerted by the positive charge of the nucleus on the negative charge of the electron. Energy is required to remove an electron from atom to overcome this attractive force.
Which formula below is the correct combination when nitrogen and hydrogen bond covalently? A. N3H B. NH3 C. NH2 D. NH
N and H covalently bond to form the correct formula NH3.
A. N3H
B. NH3
C. NH2
D. NH
A non-native organism that is released into a new ecosystem, such as Kudzu in the southeastern United States is called a
A) pioneer species.
B) threatened species.
C) endangered species.
D) non-indigenous species.
Answer is: D) non-indigenous species.
Non-indigenous species or an introduced species is a species living outside its native area, but which has arrived there by human activity, either deliberate or accidental.
Kudzu (Japanese arrowroot) was introduced from Japan into the United States at the Japanese pavilion in the 1876 Centennial Exposition in Philadelphia.
The United States Forest Service estimated the rate of spreading of plant Kudzu to be 2500 acres per year.
Answer:
D. non-indigenous species.
Explanation:
Ce procent de impuritati contine un minereu de siderit, daca din 1500kg minereu s-au obtinut 700kg fier 90% ?
FeCO3 ==> Fe + produsi minoritari.
m Fe impur= 700 kg
puritatea (p) = masa pura (mp)/ masa impura (mi) x 100
mp= p x mi / 100 sau mp = p/100 x mi => mp Fe = 90/100 x 700 = 630 kg Fe pur.
M FeCO3= 115.85 kg/kmol
115.85 kg FeCO3 .... 55.85 kg Fe
x kg FeCO3 ........630 kg Fe
x= 630 * 115.85 /55.85 = 1306.81 kg FeCO3 (mp in formula puritatii)
p=mp/mi x 100
mi FeCO3 = 1500 kg
mp FeCO3=1306.81 kg
p=1306.81 / 1500 x 100 = 87.12% puritate Siderit
You mix 145 grams of water with 200 grams of ethanol to make a solution. What is the solute and what is the solvent?
The greater amount is the solvent and the lesser amount is the solute.
Hence ethanol(200g) which is the greater amount is the solvent here.
And water (145g) which is lesser is the solute here.
Balance the equation with the correct coefficients __KCIO3 -> __KCI + ___O2
Answer: The balanced chemical reactions:
[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]
Explanation:
[tex]aKClO_3\rightarrow bKCl+cO_2[/tex]
The given reaction is an unbalanced reaction
Let 'a','b' and 'c' be the coefficient of [tex]KClO_3, KCl \text{ and } O_2[/tex] respectively.
So, in order to balance this given chemical equation:
a = 2, b = 2, c = 3
[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]
Answer:
2
2
3
in that order
Explanation: