corrected question:
A chemist determined by measurements that 0.03 moles of calcium sulfide participate in a chemical reaction. Calculate the mass of calcium sulfide that participates
Answer:
Explanation:
number of moles of CaS
molar mass of CaS = 40+32 = 72g/mol
number of moles = mass/ molar mass
mass = number of moles * molar mass
mass = 0.03 *72
mass of calcium sulfide = 2.16g
It has to be iron because oxygen doesn’t run out unless being used by something like sticking it in a bubble.
Answer:
Explanation:
Hello,
In this case, given the mathematical definition of molar concentration as the moles of solute divided by the liters of solution:
We can easily compute it by firstly computing the moles of sugar by using its molar mass:
After that, we compute the concentration by realizing 259.8 mL equals 0.2598 L:
Or just:
Considering molar units as mol/L
Best regards.
Answer:
KNO₃(s) + 35,1 kJ → K⁺(aq) + NO₃⁻(aq)
Explanation:
In the reaction:
KNO₃(s) → K⁺(aq) + NO₃⁻(aq)
The <em><u>heat absorbed</u></em> for the reaction (Because the temperature decreases) is:
Q = C×m×ΔT
Where C is specific heat (4,18J/g°C); m is mass (100g); ΔT is (30,0°C-21,6°C = 8,4°C)
Replacing:
Q = 4,18J/g°C×100g×8,4°C
<em><u>Q = 3511 J</u></em>
Now, moles of KNO₃ are:
10,1g×(1mol / 101g) = <em><u>0,1 moles.</u></em>
Heat of solution in kJ/mol is:
3,511 J / 0,1 mol = <em><u>35,1 kJ</u></em>
As the heat was absorbed for the reaction, right answer is:
<em>KNO₃(s) + 35,1 kJ → K⁺(aq) + NO₃⁻(aq)</em>
That means the reaction needs the heat to occurs.
I hope it helps!
Answer:
Freeze wedging is caused by the repeated freeze-thaw. Frost wedging occurs as the result of 9% expansion of water when it is converted to ice. Cracks filled with water are forced further apart when it freezes.
