A student mixes 0.040 mol of phosphoric acid (H3PO4\text{H}_3\text{PO}_4H3PO4) with 0.090 mol of sodium hydroxide (NaOH\text{NaOH}NaOH) in an aqueous solution. Assuming complete neutralization to form trisodium phosphate (Na3PO4\text{Na}_3\text{PO}_4Na3PO4) and water, how many molecules of water are produced?
(Use L=6.02×1023 mol−1L = 6.02 \times 10^{23}\text{ mol}^{-1}L=6.02×1023 mol−1 for Avogadro's constant)
1.81×10221.81 \times 10^{22}1.81×1022
2.41×10222.41 \times 10^{22}2.41×1022
5.42×10225.42 \times 10^{22}5.42×1022
7.22×10227.22 \times 10^{22}7.22×1022
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.