1. How is precipitate formed?
A: Particles collide, diffuse and then react.
B: Particles collide, react and then diffuse.
C: Particles diffuse, collide and then react.
D: Particles diffuse, react and then collide.
My answer is C so correct me if it is wrong.
2. A student is asked to measure the time taken for 4.00g of magnesium carbonate to react completely with 25.0 cm3 of dilute hydrochloric acid.
Which pieces of apparatus does the student need?
A: Balance, clock, pipette
B: Balance, clock, thermometer
C: Balance, pipette, thermometer
D: Clock, pipette, thermometer
My answer is c so correct me if I am wrong.
3. Chromatography and fractional distillation can be used to separate compound.
In which type of separation is a thermometer needed for checking that complete separation has occurred?
A: Chromatographic separation of two colorless solids.
B: Chromatographic separation of two solids of different colours.
C: Fractional distillation of two colourless liquids.
D: Fractional distillation of two liquid s of different colours.
My answer is B so correct me if I am wrong.
4.When written as a formulae, which compund has the greatest number of oxygen atoms?
A: Calcium
B: Copper2oxide
C: Iron3oxide
D: Potassium oxide.
My answer is D. Could you correct me if I am wrong.
5. which aqueous ion cause a white precipitate to form when acidified aqueous sliver nitrate is added to it?
A: Cloride
B: Iodide
C: Nitrate
D: Sulphate.
My answer is D so correct me.
2.A You don't need a thermometer but you do need to weigh the solid reactant
3. I am not sure about this. I don't see why a thermometer is needed for chromatography
4.C The "ferric" compound Fe2O3 has the most oxygen atoms.
5.A Both silver chloride and silver sulfate are white, but silver sulfate will not precipate in an acidic solution
3. Fractional distallation: depends on temperature, doesn't it?
for question 1
collide diffuse the react
1. The correct answer is B: Particles collide, react, and then diffuse. When two substances are mixed together, their particles come into contact and collide. If a chemical reaction occurs between the particles, a precipitate may form. In this case, the particles react with each other before they have a chance to diffuse.
2. The correct answer is A: Balance, clock, pipette. To measure the time taken for a reaction, the student needs a clock or timer. To measure the mass of magnesium carbonate accurately, a balance is required. A pipette is needed to measure a precise volume of the dilute hydrochloric acid.
3. The correct answer is C: Fractional distillation of two colorless liquids. Fractional distillation is a technique used to separate a mixture of liquids based on their boiling points. In this process, a thermometer is needed to monitor the temperature and ensure that complete separation has occurred.
4. The correct answer is C: Iron3oxide. Iron(III) oxide (Fe2O3) has the greatest number of oxygen atoms. It contains two iron (Fe) atoms and three oxygen (O) atoms, making it a compound with a total of three oxygen atoms.
5. The correct answer is A: Chloride. When acidified aqueous silver nitrate is added to a solution containing chloride ions, a white precipitate of silver chloride (AgCl) forms. This reaction is commonly used as a test for chloride ions in a solution.