Question

What is the concentration, in mol/L, where 137g of NaCl has been dissolved in enough water to make 500mL of solution?

Answer 1

Ответ:

Объяснение:

500mL=0,5 L

n(NaCl)=m(NaCl)/M(NaCl)=137/58.5=2.342 mol

C(NaCl)=n(NaCl)/V=2.342 mol/0,5 L=4.684 mol/L.

Answer 2

To find the concentration of the NaCl solution, we need to use the formula:

Concentration (in mol/L) = number of moles of solute / volume of solution (in L)

First, we need to find the number of moles of NaCl in 137g.

To do this, we need the molar mass of NaCl, which is the sum of the atomic masses of sodium (Na) and chlorine (Cl). The atomic masses of Na and Cl are 22.99 g/mol and 35.45 g/mol, respectively.

Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol

Now, we can calculate the number of moles of NaCl:

Number of moles = mass of NaCl / molar mass Number of moles = 137g / 58.44 g/mol ≈ 2.34 mol

Next, we need to convert the volume of solution from milliliters (mL) to liters (L). There are 1000 mL in 1 L.

Volume of solution = 500 mL / 1000 = 0.5 L

Now we can calculate the concentration:

Concentration (in mol/L) = 2.34 mol / 0.5 L = 4.68 mol/L

Therefore, the concentration of the NaCl solution is approximately 4.68 mol/L.