1. You have 3.0times 10^24 molecules of water (H_(2)O) . What is the mass of this sample in grams?

To find the mass of the sample, we need to use the molar mass of water and's number information:<br />- Number of molecules of water: $3.0\times 10^{24}$<br /><br />Step 1: Calculate the number of moles of water.<br />Number Number of molecules / Avogadro's number<br />Number of moles = $3.0\times 10^{24}$ molecules / $6.022\times 10^{23}$ molecules/mol<br />Number of moles = 5.0 mol<br /><br />Step 2: Calculate the mass of the sample.<br />Mass = Number of moles × Molar mass of water<br />Molar mass of water = 18.01528 g/mol<br />Mass = 5.0 mol × 18.01528 g/mol<br />Mass = 90.0764 g<br /><br />Therefore, the mass of the sample is 90.08 grams