# Chemistry

A 0.879 g sample of a CaCl2 ∙ 2 H2O / K2C2O4 ∙ H2O solid salt mixture is dissolved in 150 mL of
deionized water. A precipitate forms which is then filtered and dried. The mass of this precipitate is
0.284 g. The limiting reagent in the salt mixture was later determined to be CaCl2 ∙ 2 H2O.
(a) Write the molecular form of the equation for the reaction. (2)
(b) Write the net ionic equation for the reaction (3)
(c) How many moles of CaCl2 ∙ 2 H2O reacted in the reaction mixture? (2)
(d) How many grams of CaCl2 ∙ 2 H2O reacted in the reaction mixture? (2)
(e) How many moles of K2C2O4 ∙ H2O reacted in the reaction mixture? (1)
(f) How many grams of K2C2O4 ∙ H2O reacted in the reaction mixture? (1)
(g) How many grams of K2C2O4 ∙ H2O in the salt mixture remain unreacted? (2)
(h) What is the percent by mass of each salt in the mixture?

1. 👍 4
2. 👎 0
3. 👁 2,694
1. This looks straight forward to me but I'll get you started.
a. CaCl2.2H2O + K2CrO4 ==> CaCrO4 + 2KCl + 2H2O
b. Ca^2+ + CrO4^2- ==> CaCrO4
c. mols CaCrO4 = grams CaCrO4/molar mass CaCrO4 = ?. g = 0.284
Since 1 mol CaCl2.2H2O = 1 mol K2CrO4 in the reaction, mols CaCl2.2H2O = mols CaCrO4
d. g CaCl2.2H2O = mols CaCl2.2H2O x molar mass CaCl2.2H2O = ?
e. You see how it's done. I'll let you finish. Post your work if you get stuck.

1. 👍 3
2. 👎 4
2. DrBob, The chemistry is correct but, where did the chromate come from? I think you meant potassium oxalate monohydrate. :-)

1. 👍 0
2. 👎 0
3. Oh Crud!!. I just misread C2O4 as CrO4. But that doesn't change any of the numbers or equation. Thanks for pointing that out. My eyesight is getting really bad. Even with proofing I still made the mistake.

1. 👍 0
2. 👎 0
4. Ya got plenty of wins! Not to worry. :-)

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Chemistry

A 10.0g sample of H2O(l) at 23.0degrees C absorbs 209 joules of heat. What is the final temp of the H2O(l) sample?

2. ### chem

In a solution prepared by mixing CH3OH with H2O the major species pesent are 1. a. CH3+, OH, and H2O 2. b. CH3O, H+, and H2O 3. c. CH3OH and H2O 4. d. CH3OH, H+, and OH I know i have to get an equation having trouble doing that!!

3. ### Chemistry

Which of the following processes is endothermic? a) H2O (g) --> H2O (l) b) 3O2 (g) + 2CH3OH(g) --> 2CO2(g) + 2H2O(g) c) H2O (s) --> H2O (l) d) O2(g) + 2H2(g) --> 2H2O(g) I a guessing b, since energy has to go into the reaction for

4. ### Chemistry

The balanced net ionic equation resulting from addition of aqueous hydrochloric acid to solid chromium(III) hydroxide is: A. Cr(OH)3 (s) + 3 HCl (aq) 3 H2O (l) + CrCl3 (aq) B. Cr(OH)3 (s) + 3 Cl- (aq) 3 OH- (l) + CrCl3 (aq) C.

1. ### chemistry

Diborane (B2H6) is a highly reactive boron hydride, which was once considered as a possible rocket fuel for the U.S. space program. Calculate ∆H for the synthesis of diborane from its elements, according to the equation 2 B (s)

2. ### AP Chemistry

(a)calculate the mass percent of carbon in the hydrated form of the solid that has the formula BeC2O4 X 3 H2O (s). I divided 24.02 g by 151.08 g and got .16, or 16%. is that correct? Also, I'm having trouble with this follow up

3. ### Chemistry

which equation represents an oxidation-reduction reaction? 1.HCl+KOH-->KCl+H2O 2.4HCl+MnO2-->MnCl2+2H2O+Cl2 3.2HCl+CaCO3-->CaCl2+H2O+CO2 4.2HCl+FeS-->FeCl2+H2S

4. ### chemistry

Which of the following chemical reactions represents a neutralization reaction? A. CH4 + 2O2 CO2 + H2O B. HCl + NaOH H2O + NaCl C. NH3 + H2O NH4++ OH- D. CH3COOH + H2O CH3COO- + H3O+

1. ### chemistry

A sample of a hydrate of CuSO4 with a mass of 250 grams was heated until all the water was removed. The sample was then weighed and found to have a mass of 160 grams. What is the formula for the hydrate? CuSO4 * 10 H2O CuSO4 * 7

2. ### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -53.4 kJ : Ca(OH)2(aq) + 2 HCl(aq) CaCl2(s) + 2 H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the

3. ### Chemistry

How do I calculate number of moles of K2C2O4 in 20mL of a saturated (300g K2C2O4.H2O per liter) solution....

4. ### chemistry

Carbon dioxide (CO2) reacts with water (H2O) to form carbonic acid (H2CO3). Which equation demonstrates the law of conservation of matter for this reaction? A. 2 CO + H2O —> H2CO3 B. CO2 + H2O —> H2CO3 C. CO2 + 2 H2O —> 2