These are the answer options of this question and the comments about their validity:
<span>A) It dictates that the number of molecules on each side of a chemical equation must be the same.
False: the number of molecules can change. Take this simple reaction for example:
2H2(g) + O2 -> 2H2O
You start with 3 molecules, 2 molecules of H2 and 1 molecule of O2, and end with 2 molecules of water. Then the number of molecules of each side is different.
B) It dictates that the number of atoms of each element must be the same on both sides of a chemical equation.
TRUE: in a chemical reaction the atoms remain being the same at start and at the end of the process. Given that each atom has a characteristic mass, their conservation implies the law of conservation mass.
C) It states that the mass of the reactants must remain constant in order for a chemical reaction to proceed.
FALSE. The mass of the reactants changes during a chemical reaction, while they transform into the products.
D) It does not apply to chemical reactions.
FALSE: It is an important law used in the calculus related with chemical reactions.
</span>
To obey the Law of Conservation of Mass, the sum of all individual elements of a compound is equal to the mass of the compound. So, if HCN has a mass of 7.83 grams, then
7.83 g = mass of H + mass of C + mass of N
We know the masses of H and N to be 0.290 g and 4.06 g, respectively. Hence, we can find for the mass of C:
7.83 = 0.29 + mass of C + 4.06
mass of C = 3.48 g
As an extension to the Law of Conservation of Mass, there is also a Law of Definite Proportions. According to Dalton's atomic theory, a compound is formed from a fixed ratio of its individual elements. From our previous calculations, we know that the mass ratio of H to C to N is 0.29 g: 3.48 g:4.06 grams. The ratio could also be expressed in percentages. Let's find the mass percentage of Carbon in HCN to be used later:
mass % of Carbon = (3.48 g/7.83 g)*100
mass % of Carbon = 44.44%
So, if you collect a different mass of HCN, say 3.37 g, the corresponding mass of Carbon is equal to:
Mass of Carbon = (3.37)(44.44%)
Mass of Carbon = 1.498 g
250 kJ of energy are removed from a 4.00 x 102 g sample of water at 60˚C. Will the sample of water completely freeze: Yes, because there is enough energy.
<h3>At what temperature would a sample of water freeze?</h3>
- Note from the Facilitator: At certain temperatures, water changes its condition due to temperature variations. At sea level, fresh water changes from a solid to a liquid at 32°F (0°C). Liquid water freezes at temperatures below 32°F (0°C); this temperature is known as the freezing point of water.
- The fact that a single water molecule cannot transform into a solid, liquid, or gas is the answer. These names refer to collective behaviors of water molecules rather than to individual molecules.
- For instance, the solid (ice) has a collection of molecules that are bound together and arranged in a predictable manner. That cannot be accomplished by a single molecule alone
250 kJ of energy are removed from a 4.00 x 102 g sample of water at 60˚C. Will the sample of water completely freeze: Yes, because there is enough energy.
To learn more about water freezing, refer to:
brainly.com/question/15209660
#SPJ9
This would mean the masses of Na and Cl are 22.99g and 35.45g respectively. Therefore, the percent composition of NaCl is 39.3% sodium and 60.7% chloride.
