Question

1. how many moles are there in 1.505 × 10²⁴ molecules of water, h₂o?

Explanation:

Step1: Recall Avogadro's number

Avogadro's number, \( N_A=6.022\times 10^{23}\text{ molecules/mol}\)

Step2: Use the formula \( n=\frac{N}{N_A}\)

Here, \( N = 1.505\times 10^{24}\text{ molecules}\)
Substitute into the formula: \( n=\frac{1.505\times 10^{24}}{6.022\times 10^{23}}\)
Calculate \( n=\frac{1.505}{6.022}\times\frac{10^{24}}{10^{23}}\)
Since \(\frac{10^{24}}{10^{23}} = 10\) and \(\frac{1.505}{6.022}\approx0.25\)
\(n = 2.5\)

Answer:

\(2.5\) moles