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Atoms and reactions

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Question 67

How many hydrogen atoms are in 3.25 g of gypsum, CaSO4⋅2H2O\text{CaSO}_4\cdot2\text{H}_2\text{O}CaSO4​⋅2H2​O (Mr=172.2M_{\text{r}} = 172.2Mr​=172.2)?

A

1.14×10221.14 \times 10^{22}1.14×1022

B

2.27×10222.27 \times 10^{22}2.27×1022

C

4.55×10224.55 \times 10^{22}4.55×1022

D

6.82×10226.82 \times 10^{22}6.82×1022

Markscheme

Atoms and reactions Questions

  1. A Level
  2. /Chemistry
  3. /Atoms and reactions

199 exam-style questions on OCR A A Level Chemistry Atoms and reactions, covering Atomic structure and isotopes, Compounds, formulae and equations, Amount of substance, Acids, and Redox. Each one has a worked solution and a mark scheme showing where the marks go.

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