To 40 g of a solution containing 5% salt, add 5 g of salt. Determine the mass fraction in the solution.

univerkov | January 17, 2021 | education

Given:
m p1 (salt) = 40 g
w1 (salt) = 5% = 0.05
m в2 (salt) = 5 g
To find:
w3 (salts)
Decision:
m b1 (salt) = w1 * m p1 = 0.05 * 40 g = 2 g
m в3 (salts) = 5 g + 2 g = 7 g
m p3 (salt) = 40 g + 5 g = 45 g
w3 (salt) = m b3 / m p3 * 100% = 7 g / 45 g * 100% = 15.6%
Answer: 15.6%

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