Question

approximately how many particles are in 2 moles?
1.8 x 10²⁴
1.2 x 10²⁴
6.0 x 10²⁴
2.4 x 10²⁴
question 4
1 pts
a chemical reaction yields 3 moles of lithium hydroxide (lioh). how many grams of lithium hydroxide are present.
48 g
24 g
3 g
72 g

Explanation:

Step1: Calculate the number of particles in 2 moles

Avogadro's number \(N_A = 6.02\times10^{23}\) particles/mol.
The number of particles \(n = N_A\times moles\).
For \(moles = 2\), \(n=6.02\times 10^{23}\times2\approx1.2\times 10^{24}\)

Step2: Calculate the mass of 3 moles of \(LiOH\)

The molar mass of \(LiOH\):

• \(M_{Li}=6.94\space g/mol\), \(M_{O} = 16\space g/mol\), \(M_{H}=1.01\space g/mol\)
• \(M_{LiOH}=6.94 + 16+1.01=23.95\space g/mol\approx24\space g/mol\)
• Mass \(m = M\times moles\), for \(moles = 3\), \(m = 24\times3=72\space g\)

Answer:

For the first question: \(1.2\times 10^{24}\)
For the second question: \(72\space g\)