Answer:
C
Explanation:
According to the mole ratio, using 2NH3 will give you 3H2. Which means in order to find the moles of H2 you would only need to divide 2 and multiply 3 to get the amount of moles of H2 produced.
Air resistance depends on two important factors - the speed of the object and it's surface area. Increasing the surface area of an object decreases it's speed
Acetone will react with ammonia. Acetone will act as an Lewis Acid and ammonia will act as a Lewis Base in this situation. The nitrogen in NH3 is very reactive because of its lone pair of electrons(The nitrogen is delta -ve), so it will attack the carbon cation center of the acetone (which is delta +ve).
Answer: The ratio of carbon dioxide molecules to oxygen molecules is 20 :31
Explanation:
Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
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 balanced combustion reaction is,:

Thus the ratio of carbon dioxide molecules to oxygen molecules is 20 : 31