Answer:
q = -176kJ
Explanation:
HCl and NH3 reacts as following to NH4Cl
HCl(g) + NH3(g)=========>NH4Cl(s) : ΔH = -176 KJ
Clearly,
ENERGY IS EVOLVED MEANING IT IS A EXOTHERMIC REACTION .
therefore, the value of heat evolved as q = -176kJ
Answer: 19.4 mL Ba(OH)2
Explanation:
H2(g) + Cl2(g) --> 2HCl(aq) (make sure this equation is balanced first)
At STP, 1 mol gas = 22.4 L gas. Use this conversion factor to convert the 100. mL of Cl2 to moles.
0.100 L Cl2 • (1 mol / 22.4 L) = 0.00446 mol Cl2
Use the mole ratio of 2 mol HCl for every 1 mol Cl2 to find moles of HCl produced.
0.00446 mol Cl2 • (2 mol HCl / 1 mol Cl2) = 0.00892 mol HCl
HCl is a strong acid and Ba(OH)2 is a strong base so both will completely ionize to release H+ and OH- respectively. You need 0.00892 mol OH- to neutralize all of the HCl. Note that one mole of Ba(OH)2 contains 2 moles of OH-.
0.00892 mol OH- • (1 mol Ba(OH)2 / 2 mol OH-) • (1 L Ba(OH)2 / 0.230 M Ba(OH)2) = 0.0194 L = 19.4 mL Ba(OH)2
The formula for chromium (III) phosphate trihydrate is CrPO4- 3H20. This compound if in the anhydrous state, exists as a green crystal whereas a hydrated form violet crystal. The formula for cobalt(II) phosphate octahydrate is Co3(PO4)2•8H2O.
Explanation:
a. 0.0093
Number of significant figures = 2
All zero’s preceding the first integers are never significant
b. 120.9
Number of significant figures = 4
All zero’s between integers are always significant.
c. 1,000
Number of significant figures = 1
All zeroes used solely for spacing the decimal point are not significant.
d. 1.008
Number of significant figures = 4
All zero’s between integers are always significant.
All zero’s after the decimal point are always significant.
e. 670
Number of significant figures = 2
All zeroes used solely for spacing the decimal point are not significant.
f. 0.184
Number of significant figures = 3
All zero’s after the decimal point are always significant.
g. 1.30
Number of significant figures = 3
All zero’s after the decimal point are always significant.
its B. the alpine tundra occurs on mountaintops. just took the test.
