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The number of moles of each of the listed substances is the same. Which of these substances has more moles of equivalents?
1) CuCl2 2) Al2O3 3) H2SO4 4) AlCl3 5) BiCl3...
asked
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
0
answers
The mass of each of the listed substances is the same. Which of these substances has the largest number of moles?
1) H2SO4 2) H3PO4 3) NaF 4) CuCl2 5) CH3COOH...
asked
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Complete the phrase correctly by entering a number from the list: 0.1; 1.0; 10. If the equilibrium constant is equal to _________, then the reaction products predominate in the equilibrium mixture.
Выберите один ответ: a. 0,1 b. 10 c. 1,0 d. catalyst...
answered
Jan 20
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MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify the substance (s) in whose aqueous solutions equilibrium dissociation occurs
Выберите один или несколько ответов: a. P2O5 b. SO3 c. NO2 d. SO2 e. NO f. N2O5 g. Cl2O5 h. CO2...
answered
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Establish a correspondence between the salt and its characteristic of hydrolysis
[ on the first stage - complete decomposition ] hydrolysis of sodium sulfide hydrolysis of manganese (II) carbonate...
answered
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
For the reaction NH3(g) + HCl(g) = NH4Cl(s), ΔН<0, establish a correspondence between the direction of the equilibrium shift and the influence factors
[ no shift - shift left - shift right - no shift - shift right ] catalyst cooling heating addition of ammonium chloride pressure increase...
asked
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Establish a correspondence between the salt formula and the equivalence factor
[ f=1/3. - f=1/2 - f=1/6 - f=1 ] Ca3(PO4)2 : .......... Na2SO4 : .............. K3PO4 : ................ NaCl : ......................
asked
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
6 grams of anhydrous sulfuric acid were dissolved in 250 mL of distilled water. Specify the concentration value (s) of the resulting solution. The volume of the dissolved substance should be neglected. The density of the solution is considered equal to 1 g / mL.
Выберите один или несколько ответов: a. 0,478М b. 2,34% c. 6,0% d. 0,239N e. 0,478N...
answered
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify all of the factors listed that determine the pH of the acid buffer
Выберите один или несколько ответов: a. amount of buffer base b. рКа c. dilution d. ratio of the components [ H+ acceptor ... Ка) f. amount of buffer acid g. volume of the solution...
answered
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Based on the data on the composition of the formate (formic) buffer, specify which of the solutions can be added least of all sulfuric acid, in order not to change the pH significantly
Выберите один ответ: a. 125 mL 0,5М НСООН + 150 mL 0,75М HCOONa b. 100 mL 0,75М НСООН + 175 mL 0,5М HCOONa c. 115 mL ... mL 0,55М HCOONa d. 125 mL 0,75М НСООН + 150 mL 0,55М HCOONa...
answered
Jan 20
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MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify the substance (s) that form a buffer when sodium carbonate is added to an aqueous solution
Выберите один или несколько ответов: a. СО2 b. CaCO3 c. K2HPO4 d. KH2PO4 e. KHCO3 f. K2CO3 g. NaHCO3 h. CO...
answered
Jan 20
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MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify the pH of the sodium-acetate buffer, which is composed of 300 mL of 0,75 M acid solution and 280 mL of 1,5 M salt solution. Ka = 1,75×10-5
Выберите один ответ: a. 4,03 b. 6,03 c. 4,61 d. 5,03 e. 5,61...
answered
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
35 mL of distilled water was added to 15 mL of 0.5 mol/L aqueous ammonia solution. Specify the molar concentration of the equivalents of the resulting solution.
Choose the correct answer : a. 0,30 b. 0,25 c. 0,25 d. 0,20 e. 0,15...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Calculate the weight of the sample of crystalline soda Na2CO3 × 10H2O, which must be dissolved in a volumetric flask with a volume of 1000 mL, to obtain a mass fraction of the solute of 7%, with a density of 1.05 g /mL
Choose the correct answer: a. 7,35g b. 75,3g c. 19,83g d. 73,5g e. 198,3g...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify all the correct judgments. The value of the liquid-phase equilibrium reaction constant depends on:
a. temperatures b. precipitation c. ratio of reagents d. dispersion of a solid catalyst e. formula of the substance...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Calculate the acidity [H+] and the pH value of the solution of 0.33 mol /L of lactic acid, if α=5.3×10-2
Выберите один ответ: a. 1,076 b. 0,075 c. 2,02 d. 0,0175 e. 2,76 f. 0,033 g. 1,76 h. 0,0018...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Calculate the acidity [H+] and the pH value of the 0,35 mol/L formic acid solution using the dissociation constant Ka = 1,8×10-4
Выберите один ответ: a. 3,01 b. 0,00794 c. 2,1 d. 3,1 e. 1,1 f. 0,0794 g. 0,00079 h. 0,7937...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Calculate the acidity of the solution if pH=4,32
Выберите один ответ: a. 4,78×10-5 b. 4,78×10-4 c. 9,68...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify the salt (s) that are hydrolyzed by anion
Выберите один или несколько ответов: a. Ca(ClO3)2 b. Ca(HSO4)2 c. Ca(NO2)2 d. CaSO4 e. Ca(NO3)2 f. CaI2 g. Ca(HCOO)2 h. Ca(ClO2)2...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
0
votes
1
answer
Specify the salt (s) that correspond complete hydrolysis
Выберите один или несколько ответов: a. Ba(CN)2 b. Hg(ClO)2 c. BaCl2 d. KHSO4 e. Ba(ClO)2 f. CaBr2 g. BaSO4 h. BeS...
recategorized
Jan 20
in
MCQs
by
Dr. Ahmed Hafez
(
500
points)
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