Question

2. Определите жесткость воды, в литре которой содержится 0,486 г гидрокарбоната кальция. Сколько граммов карбоната натрия нужно прибавить к 3 м3 этой воды для устранения ее жесткости? помогите пожалуйста

Answer 1

Вот, надеюсь помогла (人 •͈ᴗ•͈)

Answer 2

Если в 1 литре воды содержится 0,486 грамм гидрокарбоната кальция, то в 3 куб. метрах (3000 литрах) — 1458 грамм.

Ca(HCO3)2 + Na2CO3 = 2NaHCO3 + CaCO3

n(Ca(HCO3)2)=m/M=1458/162=9 моль
n(Na2CO3)=n(Ca(HCO3)2=9 моль
m(Na2CO3)=n*M=9*106=954 грамм

Ответ: 954 грамм

Answer 3

Calculation of Water Hardness

To determine the hardness of water, we need to calculate the concentration of calcium carbonate (CaCO3) in the given water sample. The formula for calculating water hardness is as follows:

Water Hardness (in mg/L) = (Mass of Calcium Carbonate / Volume of Water Sample) x 1000

Given that the mass of calcium carbonate in 1 liter of water is 0.486 grams, we can calculate the hardness of the water as follows:

Water Hardness = (0.486 g / 1 L) x 1000 = 486 mg/L

Therefore, the water hardness is 486 mg/L.

Calculation of Sodium Carbonate Required

To eliminate the hardness of the water, we need to add sodium carbonate (Na2CO3). The reaction between calcium carbonate and sodium carbonate results in the formation of calcium carbonate precipitate, which can be removed from the water.

To calculate the amount of sodium carbonate required, we need to know the volume of water to be treated. In this case, the volume is given as 3 m^3 (cubic meters).

To convert cubic meters to liters, we multiply by 1000:

Volume of Water = 3 m^3 x 1000 = 3000 L

Now, we can calculate the amount of sodium carbonate required using the following formula:

Amount of Sodium Carbonate = Water Hardness x Volume of Water / 1000

Substituting the values, we get:

Amount of Sodium Carbonate = 486 mg/L x 3000 L / 1000 = 1458 grams

Therefore, 1458 grams of sodium carbonate should be added to 3 m^3 of water to eliminate its hardness.

Please note that the calculations provided are based on the given information and assumptions. It is always recommended to consult a water treatment professional for accurate and precise calculations in practical scenarios.