What statements are always true about limiting reactants? Select one or more:
1.The limiting reactant has a lower mass than other reactants.
2.The limiting reactant dictates the amount of product.
3.The limiting reactant is always the same for a given reaction.
4.There will be an excess of other reactants at the end of the reaction.
5.The limiting reactant is completely used up in the reaction.

5.The limiting reactant is completely used up in the reaction

Explanation:

The limiting reactant is completely used up in the reaction is the correct answer because a limiting reactant is a reactant in chemical reaction that is completely consumed or used up in the chemical reaction. Limiting reactant when it is completely used up limits the amount of products that will be formed. The reaction will be halted or will stop when the limiting reactant is totally used up.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"