Question

В трехлитровую банку налили 2 л воды и положили 40 грамм соли Найдите процентное содержание соли в воде как она изменилась Если через 2 дней звонки испарилась 300 грамм воды

Answer 1

2+0,04=2,04кг масса раствора
0,04:2,04*100%≈2% соль в первом растворе
2,04-0,3=1,74кг новая масса раствора
0,04:1,74*100%≈2,3% после того, как испарилось 300г воды

Answer 2

Calculation of the Percentage of Salt in Water

To calculate the percentage of salt in the water, we need to determine the initial amount of salt and the final amount of water after evaporation.

Given: - Initial volume of water = 2 liters - Initial amount of salt = 40 grams - Amount of water evaporated = 300 grams

To find the percentage of salt in the water, we can use the formula:

Percentage of salt = (Amount of salt / Final amount of water) * 100

1. Calculate the final amount of water: - Initial volume of water = 2 liters = 2000 grams - Amount of water evaporated = 300 grams - Final amount of water = Initial volume of water - Amount of water evaporated = 2000 grams - 300 grams = 1700 grams

2. Calculate the percentage of salt: - Amount of salt = 40 grams - Percentage of salt = (40 grams / 1700 grams) * 100 = 2.35%

Therefore, the initial percentage of salt in the water was 2.35%.

Please note that the above calculation assumes that the salt is evenly distributed throughout the water and that there is no other change in the composition of the solution during evaporation.