A
and it is D for your ansower
Explanation:
The most accurate way to measure a dry ingredient like flour, sugar or chocolate chips is in terms of its weight, which is measured in regular ounces.
Answer:
about 10 pounds
Explanation:
your mass doesn't change but weight changes (due to gravity)
Answer: a) 
b) 1 mole of
is produced.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The skeletal equation is:

The balanced equation will be:

Thus the coefficients are 2, 3 , 10 , 4 , 3 , 2 and 5.
b) Oxidation: 
Reduction: 
Net reaction: 
When 1 mole of
is produced, 1 mole of
is produced.
The answer is (3) Cu2O. Copper (I) has an oxidation state of +1 (that's what the "I" indicates). You can also think of this as copper (I) having a charge of +1. Oxygen has an oxidation state of -2 (that's just a rule you have to know), and you can think of it as oxygen having a charge of -2. You need oxidation numbers in a neutral compound to add up to 0 (or charges in a neutral compond to add up to 0), so you need two Cu to balance the O, which is Cu2O.