Answer
$Q = 1.34\times 10^7~C$
Work Step by Step
$250~cm^3$ of water has a mass of $250~g$
The molar mass of hydrogen is $1.0~g/mol$
The molar mass of oxygen is $16.0~g/mol$
Then the molar mass of a water molecule is $18.0~g/mol$
We can find the number of moles of water:
$\frac{250~g}{18.0~g/mol} = 13.89~mol$
We can find the positive charge:
$Q = (13.89)(6.02\times 10^{23})(10)(1.6\times 10^{-19}~C)$
$Q = 1.34\times 10^7~C$
