Question

question 19 0.1 pts part 1/2 moles, grams, molecules how many moles of na are in 5.42 x10^24 molecules na? input the numeric value. avogadro’s number: 6.022 x10^23 molecules or atoms = 1mole

Explanation:

Step1: Recall mole - molecule conversion formula

The number of moles $n$ is calculated by dividing the number of molecules $N$ by Avogadro's number $N_A$. The formula is $n=\frac{N}{N_A}$.

Step2: Substitute given values

We are given $N = 5.42\times10^{24}$ molecules and $N_A=6.022\times 10^{23}$ molecules/mole. So $n=\frac{5.42\times 10^{24}}{6.022\times 10^{23}}$.

Step3: Perform the calculation

Using the rule of exponents $\frac{a^m}{a^n}=a^{m - n}$, we have $\frac{5.42\times 10^{24}}{6.022\times 10^{23}}=\frac{5.42}{6.022}\times10^{24 - 23}$. $\frac{5.42}{6.022}\approx0.90$, and $10^{24 - 23}=10^1$. So $n\approx9.0$.

Answer:

9.0