which of these statements best describes the law of conservation of mass A) when a physical or a chemical change occurs, matter
2 answers:
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Answer:- Molar mass of .
Solution:- It is a stoichiometry problem. Mass of the grill is 30.0 kg and the mass after burning the grill is also 30.0 kg. It means all the charcol is burned and the gas is given off.
2.0 kg of charcol are converted to grams which is 2000 g. Since charcol is pure solid carbon, the grams are divided by the atomic mass of carbon which is 12.
The combustion equation of charcol is written as:
From this balanced equation, there is 1:1 mol ratio between charcol and carbon dioxide. So, the moles of carbon dioxide gas formed are equivalent to the moles of charcol. To convert the moles of carbon dioxide to grams we multiply the moles by it's molar mass.
Carbon dioxide has one carbon and two oxygen atoms so it's molar mass = 12 + 2(16) = 12 + 32 = 44
So, 44 is the molar mass of carbon dioxide and above calculations clearly shows how and where we get this.
The first step to solve this problem is to multiply the volume of solution times its concentration to find the number of moles needed, remember that M=mol/L:
Now, use the molar mass of sucrose to find the number of grams needed to make the solution. This is, multiply the number of moles needed times the molar mass:
It means that to make 0.500L of a 0.475M you will have to weigh 81.225g of sucrose.