The correct question is as follows:
How do you convert from grams to moles of a substance
1. Divide by the molar mass
2. Subtract the molar mass
3. Add the molar mass
4. Multiple by the molar mass
Answer: In order to convert from grams to moles of a substance divide by the molar mass.
Explanation:
The number of moles of a substance is the mass of substance in grams divided by its molar mass.
The formula to calculate moles is as follows.

This means that grams are converted to moles when grams is divided by molar mass.
Thus, we can conclude that in order to convert from grams to moles of a substance divide by the molar mass.
Answer:
21.4 torr
Explanation:
The vapour pressure of a solution is lower than that of the pure solvent. And according to Raoult's law this depends of the amount of solute in the solvent. It is calculated according to the following equation

where 

Constant. you have to continuously apply the same amount of force to achieve constant velocity
Elements and compounds are two types of substances ( I think). An element is any material made up of one type of atom- there could be multiples of this atom though for example oxygen which has a formula of 02. A compound is a substance made up of more than one type of atom for example H2O
Hope this helped! :)
Answer: C. enzyme
Explanation:
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and convert to products.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.
Enzymes are proteins that reduce the activation energy of biological reaction. Enzymes increase the speed of a reaction and help it to run faster. Thus they are also called as bio catalysts.
Activated complex is the transition state which is very unstable and is formed during the course when reactants are converted to products.