Answer:
a) 0.210 j
/k
b) 0.032 j/k
Explanation:
Find the attachment for solution
Answer:
0.5
Explanation:
2NaCl(s) + 2H2SO4(l) + MnO2(s) → Na2SO4(s) + MnSO4(s) + 2H2O(g) + Cl2(g)
Using ideal gas equation,
PV = nRT
28.7torr
Converting torr to atm,
= 0.0378atm
V = 0.597L
T = 27 °C
= 300 K
a) PV = nRT
(0.0378atm) * (0.597L) = n(0.0821) * (300k)
= 0.000915 mol
moles of water and chlorine = 0.000915 mol
From the above equation, the ratio of water to chlorine = 1 : 2
Therefore, mole of chlorine = 0.000915/2
= 0.000458 mol
mole fraction = moles of specie/moles of all the species present
= 0.000458/0.000915
= 0.5
To find average atomic mass you multiply the mass of each isotope by its percentage, and then add the values up.
35 * 0.90 + 37 * 0.08 + 38 * 0.02 = 35.22
Average atomic mass closest to 35.22 amu.
Answer:
8.09x10⁻⁵M of Fe³⁺
Explanation:
Using Lambert-Beer law, the absorbance of a sample is proportional to its concentration.
In the problem, the Fe³⁺ is reacting with KSCN to produce Fe(SCN)₃ -The red complex-
The concentration of Fe³⁺ in the reference sample is:
4.80x10⁻⁴M Fe³⁺ × (5.0mL / 50.0mL) = 4.80x10⁻⁵M Fe³⁺
<em>Because reference sample was diluted from 5.0mL to 50.0mL.</em>
<em>That means a solution of 4.80x10⁻⁵M Fe³⁺ gives an absorbance of 0.512</em>
Now, as the sample of the lake gives an absorbance of 0.345, its concentration is:
0.345 × (4.80x10⁻⁵M Fe³⁺ / 0.512) = <em>3.23x10⁻⁵M. </em>
As the solution was diluted from 20.0mL to 50.0mL, the concentration of Fe³⁺ in Jordan lake is:
3.23x10⁻⁵M Fe³⁺ × (50.0mL / 20.0mL) = <em>8.09x10⁻⁵M of Fe³⁺</em>
Answer:
Corn starch, one of the covalent compounds, is solid at room temperature. The property of being solid is more common to ionic compounds. So, the hypothesis was mostly supported except for this one data point.
