مقدمة في القبالة

Copper (Cu) has a density of 7.96 g/cm³ at 25 °C. What is the volume (L) of 112.3 g of Cu?

0.14

0.0141

14.1

How many grams of C are there n 55g of C₂H₅O₆ ( 125g/mol ) ?

10.56

11.56

9.56

8.56

Each oxygen atom (O) in the Lewis structure of O₂ molecule is surrounded by:

4 pairs of electrons, 1 bonding and 3 non-bonding.

pairs of electrons, 2 bonding and 2 non-bonding.

4 pairs, all bonding

4 pairs of electrons, 3 bonding and 1 non-bonding.

A 19.1 mL of a 0.875 M K₂O solution is added to 66.1 mL of 0.65 M K₃N. What is the concentration of K+ ion in the final solution?

1.9

2.6

The correct order of increase lattice energy is ...........

SrSe < KI < FrBr

KI < SrSe < FrBr

KI < FrBr < SrSe

FrBr < KI < SrSe

Beryllium reacts with a certain element to form a compound with the general formula Be₃X₂. What would the most likely formula be for the compound formed between Aluminium and element X?

AlX

Al2X3

Al3X2

Al3X

A 55-gram sample of C₃H₇O₄ ( 104 g/mol ) contains ............... atoms of H

3.7

22.29 x 10^23

0.53

3.18 x 10^23

How many grams of Mg(OH)₂ (58.3 g/mol) are present in 500mL of 0.200 M solution of Mg(OH)₂?

5.83

3.2

9.4

7.3

For the reaction 3A + 5B + 5C + 3Z → 3E + D, if equal moles of A, B ,Z and C are allowed to react in a flask, then at the end of the reaction, the flask contains:

cannot determine

A, Z, E and D

both E and D

A, E and D

Which of the following has the lowest boiling point ?

Na3N

BeO

Cs2Se

Rb2Se

Predict the empirical formula of the ionic compound that forms from potassium with oxygen

KO2

K2O

K2O2

Electronegativity ............. from bottom to Top within a group and ............... from right to left within a period

Increase , Decrease

Increase ,Increase

Decrease , Decrease

Decrease ,Increase

6.00 ng/cm³ is equivalent to .................. Gg/dm³

6.00 x 10^-15

6.00 x 10^-18

6.00 x 10^15

6.00 x 10^18

How many milliliters of 46.0 M Sulfuric acid,H₂SO₄ should be diluted with water in order to make 1.00 L of 2.00 M solution?

21.73

86.95

43.48

10.5

How many moles of MgO are consumed when 0.998 mol of Mg burns? 2Mg (s) + O2 (g) → 2MgO (s)

0.998

0.499

1.996

0.332

There are ......... milliseconds in 10000 Seconds

1 x 10^7

1 x 10^-7

1 x 10^4

1 x 10^-4

55.8 grams of O₂ (32.0 g/mol) are produced experimentally from the reaction of 45 grams of H₂O (18 g/mol) with excess CO₂ . What is the % yield in this reaction? 6CO₂ + 12H₂O ——> C₆H₂₄O₆ + 9O₂

93%

50%

1.5%

Which of the following pairs is isoelectronic ?

K,Cl-

K+,Cl

K+ , Cl-

K , Cl

Give the answer of the following calculation to the correct number of significant figures: (13.1 - 4.13) x ( 5.6 + 1.444) / 4.1

15.3

15.36

Md-term exam | Ahmad Albedaw & Obadah Alzoubi |