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# How much positive and negative charge is there in a cup (250 g) of water?

$\begin{array}{1 1}(A)\;1.34 \times 10^7 \;c \\(B)\;1.47 \times 10^7 \;c \\(C)\;2.34 \times 10^7 \;c \\(D)\;9.34 \times 10^7 \;c \end{array}$

Molecular mass of water $=18g$
No. of molecules in 18 g of water $= 6.02 \times 10^{23}$
No. of molecules in $250\; g$ of water $=\large\frac{250}{18} $$\times 6.023 \times10^{23} One molecule of water contains two hydrogen atoms and one oxygen atom, i.e., 10 electrons and 10 protons. Hence the total positive and total negative charge has the same magnitude. \qquad=\large\frac{250}{18}$$ \times 10^{29} \times 10 \times 1.602 \times 10^{-19}\;C$
$\qquad= 1.34 \times 10^7 \;C$