Question

Question one: Multiple Choice (101 mark) Circle the Best Answer of the following abow your work for numerical problems to get full credit What equipement do you use to measure accurately the density of liquid? A Top loading balance and thermometer B. Pipet, top loading balance and a beaker C Top loading balance and stopwatch D. Graduated cylinder, top loading balance and thermometer 2. The olive oil is much more soluble in non-polar solvents (than in water), because A. The olive oil is liquid B. The olive oil is non-polar The olive oil has a density higher than water D. The olive oil is polar 3. A sample of leadpiece weighing 32 g was added to a graduated cylinder partially filled with isopropyl alcohol (enough to cover the lead completely). As a result, the alcohol levelse 28.3 mil What is the density of the lead in Si units (Kg/my(1m-1000 L) (show you work) A. 113 g/mL. B 13 g/ml. C. 11.30 10 km D. 1.13 10km 4. Which of the following m oments concerning safety in the laboratory is correct? A. All chemicals should be mixed together just to see what happens B. When investigating reaction in test tube, you should look directly down the test tube C. Long hair should be tied back when working with a Bunsen humor D. Chemicals should be and before and after reaction to determine if a reaction has occurred

Answer 1

1} B) pipet ,top loading balance and a beakar

Explanation- by using pipet we can measure the exact volume of liquid take in beakar and measure the mass.

Density can calculate from the formula

Density=mass÷volume

2}B) Olive oil is non polar

Oils not contain a any polar end therefore it more soluble in non polar solvents

water is polar solvent it dissolvs polar compounds

3}D)1.13×10⁴ Kg/m³

By using archimedes principle the volume of water comes out Ias equal to volume of object means lead

Density of lead =(mass of lead) ÷(volume of isopropyl raised)

=321÷28.3

Density=11.34g/mL

4}C)Long hair should be tied back when working with a Bunsen burner

When long hair in contact with flame it started burning therefore hair should tied back properly