The moles of carbon that are in the sample of 21.45 moles of heptane(C₇H₁₆) is 150.15 moles
<u><em>calculation</em></u>
moles of carbon = moles of heptane × number of C atom
number of C atom in heptane = 1 ×7 = 7 atoms
moles is therefore = 21.45 moles × 7 =150.15 moles
Answer:

Explanation:
Hello,
In this case, the undergoing chemical reaction is:

Next, we compute the reacting moles of each reactants:


Then, as magnesium and hydrohloric acid are in a 1:2 molar ratio 0.153 moles of magnesium will completely react with 0.306 moles of hydrochloric acid yet we only have 0.144 moles, therefore, limiting reactant is hydrochloric acid. Thus, we compute the produced moles of hydrogen:

Finally, we use the ideal gas equation with T=298K and 1atm (STP conditions) to compute the liters of hydrogen gas:

Best regards.
Answer:
krypton,radon, and silicon
Answer:
The pOH is 4, 44 and the solution is basic.
Explanation:
The pOH is a measure of the concentration of OH (hydroxyl) ions in the solution.
The pOH is calculated as :
pOH = -log (OH-)= -log (3.67 x 10-5 )= 4, 44. In this case, the solution is basic.
The p0H scale ranges from values of 0 to 14 (less than 7.0 is basic and greater than 7.0 is acidic, a pH = 7.0 is neutral)
The correct answer is A. True.