Mols CuSO4 = M x L = 1.50 x 0.150 = 0.225
<span>mols KOH = 3.00 x 0.150 = 0.450 </span>
<span>specific heat solns = specific heat H2O = 4.18 J/K*C </span>
<span>CuSO4 + 2KOH = Cu(OH)2 + 2H2O </span>
<span>q = mass solutions x specific heat solns x (Tfinal-Tinitial) + Ccal*deltat T </span>
<span>q = 300g x 4.18 x (31.3-25.2) + 24.2*(31.3-25.2) </span>
<span>dHrxn in J/mol= q/0.225 mol CuSO4 </span>
<span>Then convert to kJ/mol
</span>
Answer:
Erosion is the washing away of the uppermost part of the earth crust. Once erosion starts it only gets worse because, erosion wash away further soil, causing the eroding channel to futher expand, increasing the erosion.
Lack of vegetative cover allows erosion which washes away soil nutrients, further worsening the soil against soil vegetative cover.
Answer:
Mass of chemical = 1.5 mg
Explanation:
Step 1: First calculate the concentration of the stock solution required to make the final solution.
Using C1V1 = C2V2
C1 = concentration of the stock solution; V1 = volume of stock solution; C2 = concentration of final solution; V2 = volume of final solution
C1 = C2V2/V1
C1 = (6 * 25)/ 0.1
C1 = 1500 ng/μL = 1.5 μg/μL
Step 2: Mass of chemical added:
Mass of sample = concentration * volume
Concentration of stock = 1.5 μg/μL; volume of stock = 10 mL = 10^6 μL
Mass of stock = 1.5 μg/μL * 10^6 μL = 1.5 * 10^6 μg = 1.5 mg
Therefore, mass of sample = 1.5 mg
Answer: XF8
Explanation:
Empirical Formular shows the simplest ratio of elements in a compound.
Xe = 46.3% F = 53.7%
Divide the percentage composition of each element by the atomic mass.
Xe = 46.3/ 131.3 F= 53.7/ 19
= 0.353( approx) = 2.826 (approx)
Divide through with the smallest of the answers gotten in previous step.
Xe = 0.353 / 0.353 F = 2.826/ 0.353
= 1 = 8.0
Empirical formular = XF8
Answer:
0.88g
Explanation:
The reaction equation:
2NaI + Cl₂ → 2NaCl + I₂
Given parameters:
Mass of Sodium iodide = 2.29g
Unknown:
Mass of NaCl = ?
Solution:
To solve this problem, we work from the known to the unknown.
First find the number of NaI from the mass given;
Number of moles = 
Molar mass of NaI = 23 + 126.9 = 149.9g/mol
Now insert the parameters and solve;
Number of moles = 
= 0.015mol
So;
From the balanced reaction equation;
2 moles of NaI produced 2 moles of NaCl
0.015mole of NaI will produce 0.015mole of NaCl
Therefore;
Mass = number of moles x molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Now;
Mass of NaCl = 0.015 x 58.5 = 0.88g
