You have 6 carbon atoms in glucose. Multiply by 3 and you get 18.
The mass of
is 0.185 g.
To calculate the number of moles first calculate the molar mass of
.

Molar mass of nitrogen and oxygen is 14 g/mol and 16 g/mol respectively
Thus, 
Now, number of moles can be calculated from mass and molar mass as follows:

Therefore, number of moles of 0.185 g
is 0.0042 mol.
Answer:
x=2.8moles
Explanation:
first step balance the chemical equation
C2H6+O2-->CO2+2H2O
use more ratio to find the moles of water
1mole of C2H6= 2 moles of H2O
1.4mole of C2H6=?x
cross multiply
x=2.8 moles of H2O
Answer:
7.32g of HNO3 are required.
Explanation:
1st) From the balanced reaction we know that 2 moles of HNO3 react with 1 mole of Ca(OH)2 to produce 2 moles of H2O and 1 mole of Ca(NO3)2.
From this, we find that the relation between HNO3 and Ca(OH)2 is that 2 moles of HNO3 react with 1 mole of Ca(OH)2.
2nd) This is the order of the relations that we have to use in the equation to calculate the grams of nitric acid:
• starting with the 4.30 grams of Ca(OH)2.
,
• using the molar mass of Ca(OH)2 (74g/mol).
,
• relation of the 2 moles of HNO3 that react with 1 mole of Ca(OH)2 .
,
• using the molar mass of HNO3 (63.02g/mol).

So, 7.32g of HNO3 are required.