Recent questions and answers in Chemistry

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Intermolecular Forces. Colligative properties

Main sections of lecture : STATES OF THE MATTER PHASE DIAGRAM WEAK INTERMOLECULAR INTERACTIONS PROPERTIES OF WATER ... TEMPERATURE 4.6.4 INCREASING THE SOLUTION BOILING TEMPERATURE...

answered Jan 20 in Lectures & materials by Dr. Ahmed Hafez (500 points)

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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)

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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)

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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 in MCQs by Dr. Ahmed Hafez (500 points)

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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)

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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)

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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...

answered Jan 20 in MCQs by Dr. Ahmed Hafez (500 points)

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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 : ......................

answered Jan 20 in MCQs by Dr. Ahmed Hafez (500 points)

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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)

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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)

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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...