114. What will be the final concentration of the solute when 10 ml of its 10 M solution is mixed
with 990 ml solvent?
A. 1 M
B. 0.1 M
C. 10 M
D. 0.001 M

Detailed Explanation:

When a concentrated solution is diluted by adding solvent, the total amount of solute remains constant, but the concentration decreases because the volume increases. The dilution formula is:

C1V1=C2V2C_1V_1 = C_2V_2C1​V1​=C2​V2​

Where:

• C1C_1C1​ = Initial concentration of the solute

• V1V_1V1​ = Initial volume of the solute

• C2C_2C2​ = Final concentration after dilution

• V2V_2V2​ = Final total volume after dilution

Given:

• C1=10 MC_1 = 10 \, \text{M}C1​=10M

• V1=10 mlV_1 = 10 \, \text{ml}V1​=10ml

• Solvent added = 990 ml → So, V2=10 ml+990 ml=1000 mlV_2 = 10 \, \text{ml} + 990 \, \text{ml} = 1000 \, \text{ml}V2​=10ml+990ml=1000ml

Plug into the formula:

10×10=C2×100010 \times 10 = C_2 \times 100010×10=C2​×1000 100=1000×C2100 = 1000 \times C_2100=1000×C2​ C2=1001000=0.1 MC_2 = \frac{100}{1000} = 0.1 \, \text{M}C2​=1000100​=0.1M

Final Answer:

B. 0.1 M

This means the solute is now present at a concentration of 0.1 M in the final 1000 ml solution.