Question

a student prepares 150.0 ml of 1.40 m hcl using 35.0 ml of a stock solution. what is the concentration of the stock solution? use ( m_i v_i = m_f v_f ). (\bigcirc) 0.327 m (\bigcirc) 4.29 m (\bigcirc) 6.00 m (\bigcirc) 7.35 m

Explanation:

Step1: Identify known values

We know the formula \( M_iV_i = M_fV_f \), where \( M_f = 1.40 \, \text{M} \), \( V_f = 150.0 \, \text{mL} \), and \( V_i = 35.0 \, \text{mL} \). We need to find \( M_i \).

Step2: Rearrange the formula

Rearrange the formula \( M_iV_i = M_fV_f \) to solve for \( M_i \): \( M_i=\frac{M_fV_f}{V_i} \)

Step3: Substitute the values

Substitute \( M_f = 1.40 \, \text{M} \), \( V_f = 150.0 \, \text{mL} \), and \( V_i = 35.0 \, \text{mL} \) into the formula:
\( M_i=\frac{1.40 \, \text{M} \times 150.0 \, \text{mL}}{35.0 \, \text{mL}} \)
First, calculate the numerator: \( 1.40 \times 150.0 = 210 \)
Then, divide by the denominator: \( \frac{210}{35.0}=6.00 \, \text{M} \)

Answer:

6.00 M