Question

suppose 1.535 g of copper(ii) sulfate is dissolved in water and allowed to react with 0.954 g of zinc. what is the limiting reagent? select one: sulfate cu²⁺ zn water there is no way to determine this with the provided information.

Explanation:

Step1: Write the balanced chemical equation

The reaction between copper(II) sulfate (\(CuSO_4\)) and zinc (\(Zn\)) is \(CuSO_4 + Zn=ZnSO_4 + Cu\). The mole - ratio of \(CuSO_4\) to \(Zn\) is \(1:1\).

Step2: Calculate the molar mass

The molar mass of \(CuSO_4\) is \(M_{CuSO_4}=64 + 32+4\times16 = 160\space g/mol\). The molar mass of \(Zn\) is \(M_{Zn}=65.4\space g/mol\).

Step3: Calculate the number of moles

The number of moles of \(CuSO_4\), \(n_{CuSO_4}=\frac{m_{CuSO_4}}{M_{CuSO_4}}=\frac{1.535\space g}{160\space g/mol}\approx0.0096\space mol\). The number of moles of \(Zn\), \(n_{Zn}=\frac{m_{Zn}}{M_{Zn}}=\frac{0.954\space g}{65.4\space g/mol}= 0.0146\space mol\).

Step4: Determine the limiting reagent

Since the mole - ratio of \(CuSO_4\) to \(Zn\) is \(1:1\) in the balanced equation, and \(n_{CuSO_4}(0.0096\space mol)<n_{Zn}(0.0146\space mol)\), \(CuSO_4\) (which dissociates to give \(Cu^{2 +}\) and \(SO_4^{2-}\)) is the limiting reagent. The \(Cu^{2+}\) comes from \(CuSO_4\) and it is the species that reacts (\(Cu^{2+}+Zn = Zn^{2+}+Cu\)).

Answer:

B. \(Cu^{2+}\)