Question

How many moles of sulfuric acid are required to make (4.0x10^2) mL of (1.140x10^-1) mol/L solution?
* Express your answer in scientific notation to the correct number of significant digits. Remember th:
scientific notation has one non-zero number to the left of the decimal point (i.e.: 1.23 x 104).
Note: Your answer is assumed to be reduced to the highest power possible.
Your Answer:
X10
Answer
units​

Answer 1

Answer:

See answer below

Explanation:

Hi there,

To get started, recall the formula of concentration in molar (M) units:

$c_(_M_)=\frac{n}{V_L}$  where n is the moles of the solute, and V is the volume of the solution in liters (L).

We are asked for moles, so solve for n:

$n=(c_M)(V_L)$

However, our prompt gives us volume in mL, so convert to liters (L):

$V_L=400 \ mL*\frac{1 L}{1000 \ mL} = 0.4 \ L$

$n= (1.140*10^{-1} M)(0.4 L) = 0.0456 \ mol \ H_2SO_4$

However, due to significant digit convention, when multiplying/dividing the number of s.f. conserved is the same as the number with lowest amount of s.f.. Since 0.4 contains only 1 s.f., the final answer should only contain 1 s.f. as well:

$n=0.05 \ mol \ H_2SO_4$ (rounded)

Study well and persevere.

thanks,