An alloy of copper and zinc weighing 5 kg containing 10 percent zinc was alloyed with 5 kg of pure copper.

| September 6, 2021 | education

An alloy of copper and zinc weighing 5 kg containing 10 percent zinc was alloyed with 5 kg of pure copper. Determine the percentage of zinc in the resulting alloy. how many grams of pure alcohol must be added to 735g. 16% solution of iodine in alcohol to get a 10% solution.

First task.

1. Mass of copper-zinc alloy: M = 5 kg;

2. The content of zinc in the alloy: Kz = 10% = 0.1;

3. Zinc mass: Mz = M * 0.1 = 5 * 0.1 = 0.5 kg;

4. The mass of the new alloy: Mn = M + Mm = 5 + 5 = 10 kg;

5. The percentage of zinc in the new alloy: Kzn:

Kzn = Mz / Mn = 0.5 / 10 = 0.05 or 5%.

Answer: the new alloy contains 5% zinc.

Second task.

1. Mass of iodine solution: M = 735 g;

2. The percentage of iodine: Kj = 16% = 0.16;

3. Mass of iodine: Mj = M * Kj = 735 * 0.16 = 117.6 g;

4. The mass of a new 10% solution: M1 = 117.6 / 0.1 = 1176 g;

5. It is necessary to add alcohol: Mc = M1 – M = 1176 – 735 = 441 g.

Answer: It is necessary to add 441 grams of alcohol.



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