Answer:
A scientific conclusion is best supported by results that are replicated through multiple trials.
Explanation:
<u>Answer:</u> The density of the quartz is 2.68 g/mL
<u>Explanation:</u>
We are given:
Volume of graduated cylinder = 50.3 mL
Volume of quartz + graduated cylinder = 64.8 mL
Volume of quartz = [64.8 - 50.3] mL = 14.5 mL
To calculate the density of substance, we use the equation:
Mass of quartz = 38.9 g
Volume of quartz = 14.5 mL
Putting values in above equation, we get:
Hence, the density of the quartz is 2.68 g/mL
To solve this problem, we should recall that
the change in enthalpy is calculated by subtracting the total enthalpy of the reactants
from the total enthalpy of the products:
ΔH = Total H of products – Total H of reactants
You did not insert the table in this problem, therefore I
will find other sources to find for the enthalpies of each compound.
ΔHf CO2 (g) = -393.5 kJ/mol
ΔHf CO (g) = -110.5 kJ/mol
ΔHf Fe2O3 (s) = -822.1 kJ/mol
ΔHf Fe(s) = 0.0 kJ/mol
Since the given enthalpies are still in kJ/mol, we have to
multiply that with the number of moles in the formula. Therefore solving for ΔH:
ΔH = [<span>3 mol </span><span>( − </span><span>393.5 </span>kJ/mol<span>) + 1 mol (</span>0.0
kJ/mol)<span>] − [</span><span>3 mol </span><span>( − </span><span>110.5 </span>kJ/mol<span>) + </span><span>2 mol </span><span>( − </span><span>822.1 </span>kJ/mol<span>)]</span>
ΔH = <span>795.2
kJ</span>
The molecular weight of K2SO4 is 174.26 g/mole. The mass of K2SO4 required to make this solution is calculated in the following way.
550mL * (0.76mole/1000mL) * (174.26g/mole) = 72.84gram
<span>I hope this helps.</span>
