3.3 Yield and atom economy of chemical reactions

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Question 16

This question is about the extraction of metals.

Element Z is extracted from its oxide by reduction with carbon. The equation for the reaction is:

\text{ZO} + \text{C} \rightarrow \text{Z} + \text{CO}

The sum of the relative formula masses ( $M_r$ ) of the reactants ( $ZO+C\text{ZO} + \text{C}$ ) is $93$ . Calculate the relative atomic mass ( $A_r$ ) of Z. Relative atomic masses ( $A_r$ ): $C=12\text{C} = 12$ , $O=16\text{O} = 16$

[2]

Identify element Z using your answer to part (a) and a periodic table.

[1]

Hydrogen can be used to extract tungsten ( $W\text{W}$ ) from tungsten(VI) oxide ( $WO3\text{WO}_3$ ). The equation for the overall reaction is:

\text{WO}_3 + 3\text{H}_2 \rightarrow \text{W} + 3\text{H}_2\text{O}

Calculate the percentage atom economy for extracting tungsten in this reaction. Give your answer to 2 significant figures. Relative atomic masses ( $A_r$ ): $H=1\text{H} = 1$ , $O=16\text{O} = 16$ , $W=184\text{W} = 184$

[3]

This question is about the extraction of metals.

Element Z is extracted from its oxide by reduction with carbon. The equation for the reaction is:

\text{ZO} + \text{C} \rightarrow \text{Z} + \text{CO}

[2]

Identify element Z using your answer to part (a) and a periodic table.

[1]

Hydrogen can be used to extract tungsten ( $W\text{W}$ ) from tungsten(VI) oxide ( $WO3\text{WO}_3$ ). The equation for the overall reaction is:

\text{WO}_3 + 3\text{H}_2 \rightarrow \text{W} + 3\text{H}_2\text{O}

3.3 Yield and atom economy of chemical reactions

Question 16

Markscheme

3.3 Yield and atom economy of chemical reactions

Question 16

Markscheme

3.3 Yield and atom economy of chemical reactions

Question 16

3.3 Yield and atom economy of chemical reactions Questions

3.3 Yield and atom economy of chemical reactions

Question 16

3.3 Yield and atom economy of chemical reactions Questions