Molarity how can the concentration of a solution be expressed quantitatively answer key
Final answer:
Molarity is a quantitative measure for the concentration of a solution, defined as the number of moles of solute per liter of solution, and is calculated by dividing moles of solute by liters of solution.
Explanation:
The concentration of a solution can be quantitatively expressed using molarity, which is one of the most frequently used methods by chemists. Molarity is defined as the number of moles of solute per liter of solution. To calculate the molarity of a solution, you must first determine the amount of solute in moles and then measure the total volume of the solution in liters. For example, if you have 1.5 moles of NaCl dissolved in 0.500 liters of solution, the molarity (M) of the solution is calculated by dividing the number of moles of solute by the number of liters of solution, resulting in a 3 molar (3 M) solution of NaCl.
A student cleaned a crucible with hcl. after pouring the hcl into the waste container, the crucible was neither rinsed with water nor dried before the student added the nahco3-nacl mixture. the crucible contained some residual hcl. how would this affect the calculated percentage of nahco3 in the mixture
Presence of residual HCl will react with [tex]NaHCO_3[/tex], reducing its amount and thus lower the calculated percentage of [tex]NaHCO_3[/tex] in the mixture.
If a student cleaned a crucible with HCl and then added a [tex]NaHCO_3[/tex]-NaCl mixture without rinsing or drying it, this would affect the calculated percentage of [tex]NaHCO_3[/tex] in the mixture due to the reaction between the residual HCl and [tex]NaHCO_3[/tex]. Specifically, HCl is an acid which would react with [tex]NaHCO_3[/tex], a base, to produce NaCl, [tex]CO_2[/tex], and [tex]H_2O[/tex].
[tex]NaHCO_3[/tex] (s) + HCl (aq) → NaCl (aq) + [tex]CO_2[/tex] (g) + [tex]H_2O[/tex] (l)
This reaction would decrease the amount of [tex]NaHCO_3[/tex] in the crucible, leading to a lower calculated percentage of [tex]NaHCO_3[/tex] in the mixture than actually present. This is because the [tex]CO_2[/tex] produced escapes as a gas, reducing the mass that is attributed to [tex]NaHCO_3[/tex].
The element that is shiny in appearance quite dense and liquid at room temperature is
In front of the room are 6 flasks of different sucrose solutions. the flasks contain solution that are either 0.0 m, 0.2 m, 0.4 m, 0.6 m, 0.8 m, or 1.0 m sucrose. unfortunately my colleague for got to label the flasks. devise a method for quantitatively determining which flask holds which solution.
To determine which flask holds which sucrose solution, you can use a method called titration. This involves adding a known solution that does not contain sucrose to each flask and noting when the indicator solution changes color. By comparing the volumes of the known solution required for each flask, you can determine the relative concentrations of the sucrose solutions.
Explanation:In order to determine which flask holds which solution, we can use a method called titration. Here's how it works:
Take a small sample from each flask and add a few drops of an indicator solution that changes color in the presence of sucrose.Start with the lowest concentration flask and slowly add a known concentration of a different solution (e.g., water) that does not contain sucrose.Continue to add the known solution until the indicator solution changes color, indicating that all the sucrose in the flask has reacted with the added solution.Repeat this process for each flask, starting with the lowest concentration and working your way up.By comparing the volume of known solution required to change the color of the indicator in each flask, you can determine the relative concentrations of the sucrose solutions.
________ processes such as evaporation and chemical activity can precipitate chemical sediments.
In the redox titration of Fe2+ with Ce4+ to form Fe3+ and Ce3+ what is the predominant form of cerium after 120 ml of Ce4+ has been added to the Fe2+ solution?
A.) Ce1+
B.) Ce2+
C.) Ce3+
D.) Ce4+
Actually the answer to this problem primarily depends on how much Fe2+ is initially contained in the solution. So if in case it contains more or equal amount than the cerium solution, then the answer is C. But if it has much less, then it would be D.
But I believe the answer in this case is:
C
Answer:
Ce+3
Explanation:
What is the process by which molecules of water vapor in the air become liquid water?
Which example is a density independent factor? A. rainfall B. available food C. number of possible mates D. nesting space
Which type of observation involves exact measurement, quantitative or qualitative?
Answer:
1. Quantitative
2. Qualitative
3. Qualitative
Explanation:
If you are given the mass number and atomic number of an atom explain how you would find the number of protons neutrons and electrons
What chemical property is most commonly used to classify igneous rocks?
Actually Igneous rocks are classified either based on grain size or based on mineralogy. However grain size is clearly not a chemical property. So we can say that they are classified chemically based on mineralogy or the abundance of quartz or silica present.
What caused the deflection of the alpha particles in rutherford's gold foil experiment?
The deflection of alpha particles in Rutherford's gold foil experiment was caused by the presence of a dense, positively charged nucleus within the atom that repelled the positively charged alpha particles.
Explanation:The deflection of the alpha particles in Rutherford's gold foil experiment is attributed to the presence of a dense, positively charged center or 'nucleus' in the atoms. Alpha particles, which are helium atoms that have lost their electrons and are therefore positively charged, were fired at a thin piece of gold foil. The majority of these alpha particles passed through the gold foil, suggesting that the atoms consist mostly of empty space.
However, a small fraction of the alpha particles were significantly deflected or even completely reversed direction. This indicates that these particles encountered a highly concentrated positive charge (the nucleus of the atom) that repelled the like-charged alpha particles. This deflection allowed Rutherford to deduce the presence of a small, dense nucleus within the atom, contradicting the then-established 'plum pudding' model of atom structure.
Learn more about Rutherford's gold foil experiment here:https://brainly.com/question/25094208
#SPJ12
How could you distinguish between the gases h2 and no2?
Explanation:
A molecule is defined as a substance which contains chemically bonded same type of elements.
For example, [tex]H_{2}[/tex] is a molecule and it exists as a gas which is colorless and odorless.
Hydrogen gas is represented as [tex]H_{2}[/tex].
Whereas a compound is defined as a substance which contains chemically bonded different type of elements in a fixed ratio by mass.
For example, [tex]NO_{2}[/tex] is a compound and has a reddish brown color with toxic odor.
Nitrogen dioxide is represented as [tex]NO_{2}[/tex].
For an electron in an atom to change from the ground state to an excited state, energy must be
For an electron to move from its zero or ground state to an excited state of higher energy level, of course it has to absorb energy.
Just like a person, energy must be supplied so that the person will be lively or active.
Answer:
energy must be absorbed
An electron absorb energy when change from ground state to excited state.
If an electron in an atom change from the ground state to an excited state, it must be absorb energy because with the help that energy it can move against the force of attraction of nucleus of that atom.
This energy provided to electron in order to remove the electron from outermost shell of that atom. If the electron release the energy then it comes back to its original position so we can conclude that electron absorb energy when change from ground state to excited state.
Learn more: https://brainly.com/question/6259028
A sample of 254.2 grams of copper completely reacted with oxygen to form 286.2 grams of a copper oxide product. how many grams of oxygen must have reacted?
Final answer:
To calculate the grams of oxygen that reacted, subtract the mass of copper (254.2 grams) from the mass of the copper oxide product (286.2 grams) to get 32.0 grams of oxygen.
Explanation:
To find out how many grams of oxygen reacted with copper to form copper oxide, perform a mass difference calculation from the given data. The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Therefore, the mass of products formed in a reaction equals the mass of reactants.
The initial mass of copper is given as 254.2 grams, and the final mass of the copper oxide product is 286.2 grams. To find the mass of oxygen that has combined with the copper, subtract the mass of copper from the mass of the copper oxide product:
Mass of oxygen = Mass of copper oxide – Mass of copper
Mass of oxygen = 286.2 grams – 254.2 grams
Mass of oxygen = 32.0 grams
Therefore, 32.0 grams of oxygen must have reacted with the copper.
true or false elements in the same colum have simular properties
Answer: true because they have similar chemical properties
Explanation:
Because Elements present in the same group have the same number of valence electrons.
When a hydrogen atom in one water molecule is attracted to the oxygen atom of an adjacent water molecule, a ________ bond forms.
a.covalent
b.hydrogen
c.polar
d.bipolar?
A group of scientists is trying to launch an object into orbit, and the object is traveling at 6500 m/s. Which best explains why the object will not successfully orbit Earth?
Answer:
The object is not traveling fast enough to match Earth’s curvature.
Explanation:
c on edge
Complete ground state electron configuration for the aluminum atom
Is adding hot cocoa to hot water a chemical or physical change?
Adding hot cocoa to water is a physical change because it involves combining substances without changing their chemical compositions.
Adding hot cocoa to hot water is considered a physical change. When you mix hot cocoa powder with hot water, the hot cocoa dissolves and the two substances combine, but this process does not result in new chemical substances being formed. Just like other physical changes such as the melting of ice or the dissolving of sugar in water, the composition of the resulting mixture is still a combination of water and cocoa particles.
In contrast, a chemical change involves a substance transforming into a new substance with a different chemical composition, as exemplified by iron rusting (Fe + O₂ → Fe₂O₃) or the burning of gasoline.
convert 1.5 km to millimeters, and express the result in scientific notation.
(true or false) the electron structure of an atom is determined by direct observation using x-rays.
The answer is false. It is because the electron structure of the atom is not determined by using the direct observation of using an x-ray but rather the usage of theoretical modeling and the emission spectra will be useful in observing.
Determine the volume of a 75-gram sample of gold at stp
The volume of a 75-gram sample of gold at STP is approximately 3.886 cubic centimeters, calculated using the formula V = m/d, where m is the mass and d is the density of gold.
Explanation:To determine the volume of a 75-gram sample of gold at standard temperature and pressure (STP), we must use the formula that relates mass (m), density (d), and volume (V), which is m = dV. Since the density (d) of gold is 19.3 g/cm³, we can rearrange the formula to solve for volume: V = m/d.
By plugging in the mass of the gold sample and the given density, we get:
V = 75 g / 19.3 g/cm³ = 3.886 cm³
Therefore, the volume of a 75-gram sample of gold at STP is approximately 3.886 cubic centimeters.
Learn more about Volume of Gold here:https://brainly.com/question/18459933
#SPJ3
Which regions on the periodic table can adopt positive and negative oxidation numbers?
The region(s) of the periodic table which are made up of elements that can adopt both positive and negative oxidation numbers are the “non-metal” region. As we can see on the periodic table, the elements situated at the right side of the table have two oxidation states, one positive and the other a negative.
A pill claims that it stops acne. A label on the bottle reads: "This product has not been tested by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease." What can you conclude about this product?
A. There is little evidence for this claim
B. There is no known treatment for acne
C. This product is made by doctors
D. This product will stop acne
PLEASE NEED HELP
A scientist has been collecting data on the soil composition in a forest after a wildfire. Every year she visits the forest and takes a sample from the same area. She then analyzes the sample and determines its content. She plans on collecting data for ten years and then determining the trends that have occurred. Which type of investigation is the scientist performing?
collective
comparative
experimental
descriptive
Final answer:
The scientist is conducting descriptive research, documenting soil composition changes in a forest over time without manipulating the environment.
Explanation:
The scientist performing an investigation by collecting soil composition data in a forest after a wildfire and analyzing it for trends over ten years is conducting descriptive research. This type of investigation involves documenting and describing changes in the environment without manipulating any variables. Descriptive research aims to accurately portray the characteristics of a particular individual, situation, or group over time and is foundational in natural sciences, including soil science and ecology.
In contrast to experimental research, which involves creating a controlled environment to test specific hypotheses, descriptive research documents real-world phenomena as they naturally occur. Moreover, this type of research is crucial for understanding ecological succession, how ecosystems recover after disturbances, and for guiding conservation and management practices.
When magnesium reacts with chlorine, magnesium ions (mg 2 ) and chloride ions (cl−) are formed. in this reaction, magnesium atoms?
Explain in terms of both electrons and energy how the bright line spectrum of an element is produced
Bright line spectrum is produced when electrons within an atom transition from higher energy level to lower one, emitting light at distinct wavelengths. These distinct wavelengths constitute the emission lines forming the bright line spectrum.
Each element has a unique set of such energy levels, allowing the identification of specific elements.
Explanation:The bright line spectrum of an element is produced when electrons in an atom absorb energy and move from a lower energy level to a higher one, a state known as excited state. As these electrons transition back to their original or lower energy level, they emit energy in the form of light, which is at distinct wavelengths.
These distinct wavelengths appear as a series of lines in a spectrograph, known as emission lines, and they form the bright line spectrum of an element as each element possesses its own unique set of energy levels. An understanding of such spectral lines allows us to identify specific elements present in the stars and other celestial bodies.
Learn more about Bright Line Spectrum here:https://brainly.com/question/2114602
#SPJ12
The bright line spectrum of an element is produced by the emission of photons when electrons transition from higher energy levels to lower ones. Each element has its own unique set of energy levels, resulting in a distinct pattern of spectral lines.
Explanation:The bright line spectrum of an element is produced by the emission of photons when electrons transition from higher energy levels to lower ones. Each element has its own unique set of energy levels, resulting in a distinct pattern of spectral lines. When an electron absorbs a photon and moves to a higher energy level, absorption lines are observed. These spectral lines allow scientists to identify the elements present in a substance.
Learn more about line spectra here:https://brainly.com/question/35886641
#SPJ2
If the Density of an object is 5.2 g/cm 3 , and its volume is 3.7 cm 3 , what is its mass?
Answer: mass = 19 grams
Explanation: Density is directly proportional to mass and indirectly proportional to the volume. So, the density formula is:
[tex]density=\frac{mass}{volume}[/tex]
density and volume are given and the question asks to calculate the mass. So, the formula could be rearranged as:
mass = density x volume
Given density is [tex]\frac{5.2g}{cm^3}[/tex] and the volume is [tex]3.7cm^3[/tex] .
Let's plug in the values in the formula to calculate the mass:
mass = [tex]\frac{5.2g}{cm^3}*3.7cm^3[/tex]
mass = 19.24 grams
Both the density and volume have two sig figs, so if the answer is round off to correct number of sig figs then the mass will be 19 grams.
The relative atomic mass of an atom can be found by comparing the mass of the atom to the mass of
The relative atomic mass of an atom is found out by comparing the mass of the atom to the mass of an atom of carbon-12.
What is an atom?
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
Learn more about atom,here:
https://brainly.com/question/13654549
#SPJ5