an oxygen atom has a mass of 2.66×10⁻²³ g and a glass of water has a mass of 0.050 kg. use this information…

Explanation:

Step1: Recall Avogadro's number

1 mole of any substance contains $6.022\times 10^{23}$ entities.

Step2: Calculate mass of 1 - mole of oxygen atoms

The mass of one oxygen atom is $m = 2.66\times 10^{-23}\text{ g}$. The mass of 1 mole of oxygen atoms ($M$) is the mass of one oxygen atom times Avogadro's number ($N_A=6.022\times 10^{23}\text{ mol}^{-1}$). So $M=m\times N_A=(2.66\times 10^{-23}\text{ g})\times(6.022\times 10^{23}\text{ mol}^{-1})\approx 16.0\text{ g}$.

Step3: Convert mass of water to grams

The mass of a glass of water is $m_{water}=0.050\text{ kg}$. Since $1\text{ kg} = 1000\text{ g}$, then $m_{water}=0.050\times1000\text{ g}=50\text{ g}$.

Step4: Calculate moles of oxygen atoms equal to mass of water

The number of moles ($n$) of oxygen atoms with a mass equal to the mass of water is given by $n=\frac{m_{water}}{M}$. Substituting $m_{water} = 50\text{ g}$ and $M = 16.0\text{ g/mol}$, we get $n=\frac{50\text{ g}}{16.0\text{ g/mol}}\approx 3.1\text{ mol}$.

Answer:

What is the mass of 1 mole of oxygen atoms? 16.0 g How many moles of oxygen atoms have a mass equal to the mass of a glass of water? 3.1 mol