Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.
Example:
There are 5g of water.
Calculate the amount of moles.
The water's formula is H2O, so the molar mass of it is

g/mol.
The amount of moles is:
5g ÷ 18g/mol ~ 0.28mol
Average atomic mass listed for nitrogen in the periodic table is 14
Hope this helps!
An an increase in
temperature lead to more effective collisions between reactant particles and an
increase in the rate of a chemical reaction because the number of
molecules with sufficient energy to react increases. The answer is number 3.
Answer: 2NOBr(g) ⇌ 2NO(g) + Br2(g)
Explanation: For volume changes in equillibrium, the following are to be taken into consideration:
- Volume changes have no effect on equillibrium system that contains solid or aqueous solutions.
- An increase in volume of an equilibrium system will shift to favor the direction that produces more moles of gas.
- A decrease in volume of an equilibrium system will shift to favor the direction that produces less moles of gas.
- Volume changes will have no effect on the equillibrium system if there is an equal number of moles on both sides of the reaction.
2NOBr(g) ⇌ 2NO(g) + Br2(g) is the equillibrium system because there are more moles of products,therefore an increase in the volume of the reaction will shift to the right and produce more moles of products. Also both reactants and products exist in the gaseous state and does not have equal number of moles.