Answer:
Explanation if an object is in motion and more force is applied to it, the object will begin moving faster. If two objects have the same mass and a greater force is applied to one of the objects, the object which receives the greater force will change speeds more quickly.:
Mg gained mass because it went from being a single element (on the reactant side) to being a molecule (on the product side).
Answer:
The percent by mass of copper in the mixture was 32%
Explanation:
The ammount of HNO₃ used is:
mol HNO₃ = volume * concentration
mol HNO₃ = 0.015 l * 15.8 mol/l
mol HNO₃ = 0.237 mol
According to the reaction, 4 mol HNO₃ will react with 1 mol Cu and produce 1 mol Cu²⁺. Since we have 0.237 mol HNO₃, the amount of Cu that could react would be (0.237 mol HNO₃ * 1 mol Cu / 4 mol HNO₃) 0.06 mol. This reaction would produce 0.060 mol Cu²⁺, however, only 0.010 mol Cu²⁺ were obtained, indicating that only 0.010 mol Cu were present in the mixture. This means that the acid was in excess, so we can assume that all copper present in the mixture has reacted.
Since 0.010 mol of Cu²⁺ were produced, the amount of Cu was 0.01 mol.
1 mol of Cu has a mass of 63.5 g, then 0.01 mol has a mass of:
0.01 mol Cu * 63.5 g / 1 mol = 0.635 g.
Since this amount was present in 2.00 g mixture, the amount of copper in 100 g of the mixture will be:
100 g(mixture) * 0.635 g Cu / 2 g(mixture) = 32 g
Then, the percent by mass of Cu (which is the mass of Cu in 100 g mixture) is 32%
<span>Fe atomic mass = 55.86
* 1 = 55.86
Cr atomic mass = 52
*2 = 104
O atomic mass = 16
* 4 = 64
Total molecular mass = 223.86
Percent by mass Fe = (55.86/223.86)*100 = 24.95%
Percent by mass Cr = 46.45%
Percent by mass O = 28.59%</span>
I would say it is A because it can be a group of atoms. idk
