How many grams of sodium bicarbonate are needed to make 400 ml of a 1:1000 w/v solution?

To determine how many grams of sodium bicarbonate are needed to make 400 ml of a 1:1000 w/v solution, it is important to understand what a 1:1000 w/v solution means. The "w/v" stands for weight/volume, indicating there is 1 gram of solute (in this case, sodium bicarbonate) for every 1000 ml of solution.

For a 1:1000 solution, if we have 1000 ml, we would need 1 gram of sodium bicarbonate. Therefore, for 400 ml, we can set up a simple proportion to find out how much sodium bicarbonate is needed.

1. First, recognize that 1000 ml equals 1 gram of sodium bicarbonate.

2. We need to find the weight for 400 ml.

Using the formula:

(grams of sodium bicarbonate) = (1 gram / 1000 ml) × 400 ml

Calculating this gives:

(1 gram / 1000 ml) × 400 ml = 0.4 grams

Thus, for 400 ml of a 1:1000 w/v solution, you need 0.4 grams of sodium bicarbonate, which corresponds