Ethanol/water mixtures
Mixture M from 2 liquids A and B
Volume/volume percentage (Percentage by volume) of A:
$%\; in\; volume\; of\; A$ $=$ $\frac{V_A\cdot 100}{V_M}$
Percentage (by mass) of A:
$%\; (in\; mass)\; of\; A$ $=$ $\frac{m_A\cdot 100}{m_M}$
(Volumetric) mass density of A $(\;\rho_A\;)$:
$\rho_A$ $=$ $\frac{m_A}{V_A}$
Relative density of A $(\;d_A\;)$:
$d_A$ $=$ $\frac{\rho_A}{\rho_{eau}}$
When mixing two liquids, the masses add up, but not necessarily the volumes!
Consult the ethanol / water tables here
At $ 20^oC $ $ 50.00\; mL $ of ethanol is mixed with $ 50.00\; g $ of water.
Calculate using → tables the mass of ethanol !
For answers, use (possibly multiple times) the arrows ↑ and ↓ at the top!
Complete please this question before moving on to the next!
$m$ $=$ $\rho \cdot V$ $=$ $0,78945\cdot 50,00$ $ =$ $39,47\; g$
Then calculate the percentage by mass of ethanol !
$\%$ $=$ $\frac{m_{ethanol}\cdot 100}{m_{mixture}}$ $=$ $44,12$
