The group of atoms held together by covalent bonds is called a molecule
Explanation:
2. 
First, we need to find the number of moles of
at 300K and 1.5 atm using the ideal gas law:


Now use the molar ratios to find the number of moles of ethane to produce this much
.


Finally, convert this amount to grams using its molar mass:


3. 
Convert 75 g Zn into moles:

Then use the molar ratios to find the amount of H2 produced.

Now use the ideal gas law
to find the volume of H2 produced at 23°C and 4 atm:


Answer:
If you are given a chemical equation and specific amounts for each reactant in grams, you have to follow these steps, in order, to determine how much product can possilby be made:
1. Convert each reactant into moles of the product.
2. Determine which reactant is the limiting reactant.
3. Convert the moles of product, from the limiting reactant, to grams.
Explanation: