Answer:
TRUE
Explanation:
Main job of calorimeter is to measure energy changes or determine specific heat capacity of different substances. Specific heat is an intensive property (like density, color, etc.) that does not depend on the amount of a substance present. This allows substances to be identified using their specific heat. Thus, calorimeter comes very handy in determining the specfic heat of unknown substance.
Answer: 0.25
Explanation: M = moles of solute / volume of solution (L)
First, you need to calculate the number of moles using the given mass and the molar mass.
15 g74.692 g/mol≈0.20 mol
Then, you can solve for molarity using the molarity equation. The answer should be reported to two significant figures.
M=0.20 mol/ 0.800 L = 0.25 M
Answer:
Ka = 0.1815
Explanation:
Chromic acid
pH = ?
Concentration = 0.078 M
Ka = ?
HCl
conc. = 0.059M
pH = -log(H+)
pH = -log(0.059) = 1.23
pH of chromic acid = 1.23
Step 1 - Set up Initial, Change, Equilibrium table;
H2CrO4 ⇄ H+ + HCrO4−
Initial - 0.078M 0 0
Change : -x +x +x
Equilibrium : 0.078-x x x
Step 2- Write Ka as Ratio of Conjugate Base to Acid
The dissociation constant Ka is [H+] [HCrO4−] / [H2CrO4].
Step 3 - Plug in Values from the Table
Ka = x * x / 0.078-x
Step 4 - Note that x is Related to pH and Calculate Ka
[H+] = 10^-pH.
Since x = [H+] and you know the pH of the solution,
you can write x = 10^-1.23.
It is now possible to find a numerical value for Ka.
Ka = (10^-1.23))^2 / (0.078 - 10^-1.23) = 0.00347 / 0.0191156
Ka = 0.1815
Answer:
5
Explanation:
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