Answer:
37.5 g NaCl
Explanation:
Step 1: Given data
- Concentration of NaCl: 15.0% m/m
- Mass of the solution: 250.0 g
Step 2: Calculate how many grams of NaCl are in 250.0 g of solution
The concentration of NaCl is 15.0% by mass, that is, there are 15.0 g of NaCl every 100 g of solution.
250.0 g Solution × 15.0 g NaCl/100 g Solution = 37.5 g NaCl
Answer: -
37.5 g of NaCl are in 250 g of a 15.0% (by weight) solution.
Explanation: -
Total mass = 250 g
Percentage of NaCl = 15.0 %
= 
Thus 
= 
Number of grams of NaCl present = 
= 37.5 g
D has the fastest reaction rate because dynamite explodes almost immediately.
A isn't correct because rusting nails take forever to completely rust.
B isn't correct because logs burning can take around 10 to 20 minutes.
C isn't correct because food digestions takes anywhere between 10 minutes to an hour.
Number of moles = volume / (molar volume)
Molar volume at stp = 22.4 dm^3
Volume = no of moles × molar volume
= 0.987 × 22.4
= 22.1088 dm^3
= 22108.8 cm^3
Hope it helped!
B. Slower than the gas is the answer
