Answer
79 ml
Explanation
You have 237 237 ml of ammonia, whose strength is 100%.
If you want to make it 75%, then;
let 75% ⇒ 237 ml of ammonia and
25% ⇒ x ml of water.
∴ x = (25% ×237) / 75%
= 5,925/75
= 79 ml of water.
Explain why it is important to change only one variable in an experimental setup
When adding one atom has 20 protons and a mass of 44. another atom has 20 protons and a mass number of 40. what is the identity of these atoms?
The atoms are both isotopes of calcium (atomic number 20). One isotope has a mass number of 40 (40Ca), which means it has 20 neutrons, while the other isotope has a mass number of 44 (44Ca), which means it has 24 neutrons.
Explanation:When two different atoms have the same number of protons but different mass numbers, they are known as isotopes of the same element. In this case, since both atoms have 20 protons, they are isotopes of the element with the atomic number 20, which is calcium.
The identity of an atom is defined by its number of protons, which is the atomic number. For calcium, the atomic number is indeed 20. The mass number, which is given as 40 and 44 in the two variants, represents the total number of protons and neutrons in the nucleus. To find the number of neutrons in each isotope:
For the isotope with a mass number of 40: number of neutrons = 40 - 20 = 20.For the isotope with a mass number of 44: number of neutrons = 44 - 20 = 24.Therefore, the isotopes of calcium can be represented as 40Ca (20 protons and 20 neutrons) and 44Ca (20 protons and 24 neutrons).
Which term is best defined as a measure of the amount of space a substance occupies?
The term 'Volume' in physics defines the measure of the amount of space that a substance occupies. It is used across various equations and calculations in the study of physical sciences. Its applicability ranges from classroom learnings to real-life situations.
Explanation:The term that best defines the measure of the amount of space a substance occupies is Volume. Volume is a fundamental concept in physical sciences and is often used in equations and calculations. Whether the substance is a liquid, a gas, or a solid, you can calculate its volume. For instance, the volume of a solid box is calculated by length * width * height, and the volume of a liquid in a cylindrical container would be calculated with π*radius2*height. Knowledge of volume can apply to real-life situations beyond the classroom as well, like working out how much water you can fit in a pool, or how much air is in your bedroom.
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When a substance undergoes a physical change does it create a new substance?
List the three components of traditional cell theory.
Answer:
flowers
rocks
blood
water
bacteria
sugar
skin
Determine the mass of 18.7ml of rubbing alcohol with a density of 0.79 g/ml?
Answer:
The mass of the rubbing alcohol is 14.77 g
Explanation:
The formula to be used here is that of density which is shown below
Density = Mass ÷ volume
The density of the rubbing alcohol (also known as isopropyl alcohol) is given in the question as 0.79 g/ml while the volume of same is given as 18.7ml. The mass of this rubbing alcohol is the unknown (which we can derive from the formula given earlier).
Hence,
Mass = Density × volume
Mass = 0.79 × 18.7
Mass = 14.77 g
What is the molality of a solution that contains 5 moles of solute in 100 kilograms of water?
Answer:
[tex]m=0.05m[/tex]
Explanation:
Hello,
In this case, molality is defined as:
[tex]m=\frac{n_{solute}}{m_{solvent}}[/tex]
Whereas the mass of the solvent is given in kilograms. In such a way, for 5 moles of solute and 100 kg of water, the molality turns out:
[tex]m=\frac{5mol}{100kg}\\ m=0.05\frac{mol}{kg}[/tex]
Now it is important to notice that the molal units (m) equals mol/kg, thereby:
[tex]m=0.05m[/tex]
Best regards.
Molecules and atoms. which is more massive: an atom, a molecule, an isotope, or an ion?
Calculate the energy of a quantum of radiant energy with a frequency of 5.00x1011/s
Which would be expected to have a higher boiling point t-butyl alcohol or n-butyl alcohol?
What is the frequency of electromagnetic radiation having a wavelength of 3.27 ✕ 10-8 m?
s-1 What type of electromagnetic radiation is this?
Which of the following elements is the most reactive?
Chlorine
Bromine
Fluorine
Helium
Answer:
Fluorine
Explanation:
How many grams of cl are in 445 g of cacl2?
Why using a temperature probe is preferable to using a conventional mercury thermometers
what physical properties are used when making a cup of tea by boiling a tea bag in hot water?
Physical properties can be perceived or observed without changing the structure of matter. These are used to detect and describe matter. Physical properties comprise: appearance, texture, color, odor, boiling point, melting point, density, solubility, and polarity just to name a few.
In this case, the physical process used is boiling, which causes water to evaporate and the contents in the tea bag to become more soluble and can make the color to change. Also, the physical property of solubility relates to some of the components of the tea.
Which has the greater density?
air at sea level
air at 20 km altitude
in which section of the Periodic Table are the most active metals located
Answer:
bottom left corner
Explanation:
These are where their located
The metals in the bottom left corner of the periodic table are the most active in the sense that they are the most reactive. For example, lithium, sodium, and potassium all react with water.
What is periodic table ?The periodic table is a tabular array of chemical elements organized by atomic number, beginning with hydrogen and progressing to oganesson, which has the highest atomic number.
An element's atomic number is the number of protons in the nucleus of an atom of that element. There is one proton in hydrogen and 118 in oganesson.
Caesium, the most reactive metal in the periodic table, reacts violently, which is why it cannot be demonstrated in a classroom. When other common metals, such as iron and copper, are dropped into water, they produce no reaction.
Thus, The most reactive metals in the bottom left corner of the periodic table.
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Why is the periodic table such as useful tool for chemist?
Enzymes work by _____. enzymes work by _____. decreasing the potential energy difference between reactant and product adding energy to a reaction reducing ea adding a phosphate group to a reactant increasing the potential energy difference between reactant and product
Enzymes work by lowering the activation energy, making the reaction faster. They bind to reactants, presenting them in a manner that speeds up the bond breaking/formation. Enzymes don’t change the free energy; they only reduce the activation energy.
Explanation:Enzymes work by lowering the activation energy of a chemical reaction, thus speeding up the reaction rate. Enzymes accomplish this by binding to the reactant molecules and positioning them in a manner that facilitates the bond-breaking and bond-forming processes more readily. They essentially act as catalysts within a cell.
The enzyme contains an active site that provides a unique chemical environment made up of amino acid R groups. This active site is perfectly suited to convert particular chemical reactants known as substrates into unstable intermediates called transition states. The binding of enzymes and substrates follow an induced-fit model, where the enzyme undergoes slight adjustments upon substrate contact, resulting in full, optimal binding.
Contrary to some misconceptions, enzymes don't alter the free energy of the reactants or the products. They only reduce the activation energy required for the reaction to proceed. After the reaction, the enzyme itself does not undergo any change and can participate in other reactions.
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Which of the following measurements is equal to 2.3 dL?
23 L
2,300 cL
23,000 mL
230,000 µL
Which of the following measurements is equal to 2.3 dL?
23 L
The correct measurement equal to 2.3 dL is 230,000 µL.
To find the equivalent measurement, we need to understand the relationship between different units of volume in the metric system. The prefixes used in the metric system are as follows:
- deci- (d) means one-tenth (1/10)
- centi- (c) means one-hundredth (1/100)
- milli- (m) means one-thousandth (1/1000)
- micro- (µ) means one-millionth (1/1000000)
Now, let's convert 2.3 dL to liters, then to centiliters, milliliters, and micro liters:
1. Since 1 deciliter (dL) is equal to 0.1 liters (L), we have:
[tex]\[ 2.3 \text{ dL} = 2.3 \times 0.1 \text{ L} = 0.23 \text{ L} \][/tex]
2. To convert liters to centiliters (cL), we know that 1 L is equal to 100 cL:
[tex]\[ 0.23 \text{ L} = 0.23 \times 100 \text{ cL} = 230 \text{ cL} \][/tex]
3. To convert liters to milliliters (mL), we know that 1 L is equal to 1000 mL:
[tex]\[ 0.23 \text{ L} = 0.23 \times 1000 \text{ mL} = 230 \text{ mL} \][/tex]
4. To convert liters to micro liters (µL), we know that 1 L is equal to 1,000,000 µL:
[tex]\[ 0.23 \text{ L} = 0.23 \times 1,000,000 \text{ µL} = 230,000 \text{ µL} \][/tex]
Given these conversions, we can now match the equivalent measurement to the options provided:
- 23 L is incorrect because 2.3 dL is equivalent to 0.23 L, not 23 L.
- 2,300 cL is incorrect because 2.3 dL is equivalent to 230 cL, not 2,300 cL.
- 23,000 mL is incorrect because 2.3 dL is equivalent to 230 mL, not 23,000 mL.
- 230,000 µL is correct because 2.3 dL is equivalent to 230,000 µL.
Therefore, the correct answer is 230,000 µL.
The atomic weight of boron is reported as 10.81, yet no atom of boron has the mass of 10.81 amu. explain
Using your own words define a scientific law
Why do you need to make an ice water slush mixture (instead of only ice) in order to calibrate your thermometer at 0°c?
An ice water slush mixture is used to calibrate thermometers at 0°C because it guarantees the temperature stays constant due to the thermal equilibrium between the melting ice and water, providing a precise reference for calibration.
Explanation:To calibrate a thermometer at 0°C, it is necessary to use an ice water slush mixture rather than just ice. The reason for this is that the mixture of ice and water will be in thermal equilibrium, ensuring that the temperature remains consistently at 0°C. This equilibrium state occurs because the melting ice absorbs heat without a change in temperature until it completely transitions to liquid water.
The presence of ice ensures that any heat added to the system does not increase the temperature but instead is utilized to change the phase of the ice to water. This phenomenon is why a cup of water with ice cubes remains at 0°C on a hot day and why it is essential for the mixture to have both ice and liquid water to create an accurate calibration point for the thermometer.
How does a solution of ph 7 compare to a solution of ph 10?
Why is it advisable to keep the storage bottle containing the naoh solution closed?
A salt crystal has a mass of 0.17 mg . how many nacl formula units does it contain?
Scientist who have a chemical element named after them
A force acts on an object and moves it a certain distance. The product of the force and the distance is the
done on the object.
What element does not prefer to react with other elements?
The type of bonding and the numbers of covalent bonds an atom can form with other atoms are determined by __________.
The type of bonding and the number of covalent bonds an atom can form are determined by its valence electrons, which influence the atom's ability to share electrons and achieve a stable outer electron shell.
The type of bonding and the number of covalent bonds an atom can form with other atoms are determined by its valence electrons. These are the electrons that are found in the outermost shell of an atom and are involved in bonding. Atoms form covalent bonds by sharing valence electrons with other atoms to achieve a full outer shell, resembling the electronic configuration of noble gases. The number of covalent bonds that an atom can form is generally equal to the number of additional electrons needed to fill its outer shell.
For example, carbon, which has four valence electrons, can form four covalent bonds because it needs four more electrons to complete its octet. Similarly, nitrogen, with five valence electrons, typically forms three covalent bonds, as it requires three more electrons to have a full octet, and oxygen with six valence electrons most often forms two covalent bonds.