For the reaction HCl + NaOH → NaCl + H2O, how many moles of hydrochloric acid are required to produce 281.0 g of water?

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To determine the number of moles of hydrochloric acid required to produce 281.0 g of water, we need to use the balanced equation for the reaction and the molar mass of water.

The balanced equation is:
HCl + NaOH → NaCl + H2O

The molar mass of water (H2O) is:
H = 1.008 g/mol
O = 16.00 g/mol

Therefore, the molar mass of water is:
1.008 g/mol + 16.00 g/mol = 18.01 g/mol

Now, let's find the number of moles of water using its mass:
Mass of water = 281.0 g
Molar mass of water = 18.01 g/mol

Number of moles of water = Mass of water / Molar mass of water
Number of moles of water = 281.0 g / 18.01 g/mol

Calculating this, we find:
Number of moles of water = 15.554 mol (rounded to three decimal places)

Since the balanced equation shows a 1:1 ratio between hydrochloric acid (HCl) and water (H2O), the number of moles of hydrochloric acid required will also be 15.554 mol.