What is the molarity of a solution made by dissolving 4.14 g of sodium acetate in water and diluting to 750. mL? (molar mass NaC2H3O2 is 82.0 g/mol.)

.67137, but that wasn't right.

An open-ended mercury manometer is used to measure the pressure exerted by a trapped gas as shown in the figure. Atmospheric pressure is 750. mmHg. What is the pressure (in mmHg or torr) of the trapped gas if h =23 cm?

I got 893.462, but that was also wrong. Any help please?

mols NaAc = grams/molar mass

M = mols/0.750L = ? = about 0.06

Thanks! Do you think you can help with the second one?

To find the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters).

In the first question, you are given the amount of sodium acetate in grams and the volume of the solution in milliliters. To start, you need to convert the grams of sodium acetate to moles. You can do this using the molar mass of sodium acetate, which is 82.0 g/mol.

Step 1: Convert grams to moles.
4.14 g NaC2H3O2 * (1 mol NaC2H3O2 / 82.0 g NaC2H3O2) = 0.0505 mol NaC2H3O2

Step 2: Convert milliliters to liters.
750. mL * (1 L / 1000 mL) = 0.750 L

Now that you have the amount of solute in moles and the volume of the solution in liters, you can calculate the molarity using the formula:

Molarity = moles of solute / volume of solution (in L)

Molarity = 0.0505 mol / 0.750 L = 0.0673 M

Therefore, the molarity of the solution is 0.0673 M.

Regarding the second question about the pressure of the trapped gas, you are given the height (h) of the mercury column in centimeters. To find the pressure in millimeters of mercury or Torr, you can use the following relationship:

Pressure (in mmHg or Torr) = h (in cm) - atmospheric pressure

Given that the atmospheric pressure is 750 mmHg, you can substitute the value of h into the equation:

Pressure = 23 cm - 750 mmHg = -727 mmHg

Please note that the negative sign indicates that the pressure is below atmospheric pressure. Therefore, the pressure of the trapped gas in this case is -727 mmHg.