What volume of distilled water should be added to 400cm3 of 2.0 mole dm-3 (H_{2}SO_{4}) to obtain 0.20 mole dm-3 of solution>
-
A.
600cm-3 -
B.
800cm-3 -
C.
1,000cm-3 -
D.
3,600cm-3 -
E.
4,000cm-3
Correct Answer: Option D
Explanation
(400cm^{3} to 2moldm^{-3})
(0.4 dm^{3} to 2moldm^{-3})
Multiplying in order to get the moles of the acid.
(0.4dm^{3} times 2moldm^{-3} = 0.8moles)
After diluting to (0.2moldm^{-3}), the new volume will be
(frac{0.8}{0.2} = 4dm^{3})
Converting back to cm^3,
We have (4 times 1000cm^{3} = 4000cm^{3})
Hence, the volume of water added = ((4000 – 400)cm^{3} = 3600cm^{3})