General Chemistry Answers

Mass of crucible+lid+Mg= 10.90

Crucible+lid= 10.03

Mass of MgO formed - Mass of crucible= 10.90-10.03= 0.87

Calculate:

Mass of MgO

Amount of Mg in the compound

Mass of O2 in the compound

Amount of oxygen in mole

Simple number ratio to oxygen to Mg

Empirical formula of the compound.

10.6 g of anhydrous sodium carbonate combines with 18g of water to form hydrated sodium carbonate whose chemical formula is ….                (Na=23, C=12, O=16, H=1)

1) Iron can be produced when iron (III) oxide reacts with carbon monoxide gas. /5

Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g)

11.5 g of Fe2O3 reacts with 2.63 x 1024 molecules of CO. What mass of Fe is expected?

1. A solute which forms a solution capable of conducting electricity is best described as a(n)

(a) good conductor

(b) anode

(c) electrolyte

(d) cathode

Calculate the density of ammonia at 30 degree Celsius and 5 atmospheric pressure

5 litre of a gas at a pressure of 2 atmospheric pressure and a temperature of 27 degree Celsius is heated to 227degree celcius and the pressure is raised to 6 atmospheric pressure . What is the volume under these conditions

Calculate the solubility in mol/dm of 40g of CuSO4 dissolved in 100g of water at 120 degrees Celsius

AGREE OR DISAGREE?

1. Mole is an expression of the amount of substance.

2. Mole is equivalent to 60.2 x 1023 particles.

3. Each atom in the periodic table has the same number of mole but different atomic mass.

4. A mole of different substances, example gold and silver, has different number of particles.

5. One mole of an element is equal to its atomic mass.

6. Molar mass is the mass of one mole of a compound, example NaCl

7. Atom is used to refer to the particle of element and molecule for compound.

8. To convert the given mass of NaCl, to number of mole, we simply divide the given mass to its molar mass.

9. The particle of ionic compound is called ion. 

10. To determine the number of molecules in 1 mole of NaCl or salt, we multiply it with 6.02 x 1023 molecules.

illustrate using a concept map the process on how to compute the molecular formula of a certain substance, given its percentage composition.

Give the percentage composition of sodium hydrogen carbonate (NaHCO3) or baking soda. Baking soda is an active ingredient in some you antacids like Kremil-S.