Question

question 4 (1 point)
which of the following correctly gives the correct coefficients for the reaction below?
n₂h(g) + h₂o₂(l) → n₂(g) + h₂o(g)
1,1,1,1
1,2,1,4
1,4,1,4
2,4,2,4
question 5 (1 point)
how many moles of k are in 15.0 g of k₂so₄?
174.2 mol
0.0861 mol
0.172 mol
0.344 mol

Explanation:

Step1: Calculate molar mass of \(K_2SO_4\)

Molar mass of \(K = 39.1\space g/mol\), \(S = 32.07\space g/mol\), \(O = 16.0\space g/mol\).
Molar mass of \(K_2SO_4=2\times39.1 + 32.07+4\times16.0\)
\(=78.2+32.07 + 64\)
\(=174.27\space g/mol\)

Step2: Calculate moles of \(K\)

Moles of \(K_2SO_4=\frac{mass}{molar\space mass}=\frac{15.0\space g}{174.27\space g/mol}\approx0.0861\space mol\)
In \(K_2SO_4\), there are 2 moles of \(K\) per 1 mole of \(K_2SO_4\).
Moles of \(K = 2\times0.0861\space mol = 0.172\space mol\)

Answer:

\(0.172\space mol\)