Exercises

1. Match English word combinations with their Ukrainian equivalents.

1. a wide variety of substances

2. a highly corrosive and poisonous liquid

3. to take place at high temperatures

4. to be used mainly in laboratory

5. commercial production

а. промислове виробництво

b. велика різноманітність речовин

c. використовуватися головним чином в лабораторії

d. відбуватися при високих температурах

e. високоактивна і отруйна рідина

2. Answer the questions.

1. What kind of liquid is hydrochloric acid?

2. How is hydrochloric acid formed?

3. How much hydrogen chloride does commercial hydrochloric acid contain?

4. Where is hydrochloric acid used?

5. How is hydrogen chloride prepared?

Solutions

We know a solution to be a uniform mixture of one substance in another. The material to be dissolved is the solute and the substance which does the dissolving is the solvent. The rate at which a substance may be dissolved can be controlled in several ways. The surface area, the agitation, and the temperature all are found to have an effect on the rate of solution. The ease with which a substance may be dissolved is known to be its solubility. The solubility of solid, liquid, or gaseous solutes is determined by a number of factors, such as the nature of the solvent, the nature of the solute, the temperature and the pressure. In a solution the solute cannot be separated from the solvent by filtration.

The concentration of solute in solution may vary from dilute (a small amount of solute relative to the solvent) to concentrated (a large amount of solute relative to the solvent). The most common of the solvents is known to be water. Among the organic compounds such materials as alcohol and benzene are commonly used solvents. Most organic compounds can be dissolved only in organic solvents.

Vocabulary

agitation - коливання mixture - суміш amount - кількість rate - швидкість benzene - бензол relative - відносний common - загальний solubility - розчинність

determine - визначати solute – розчинна речовина dilute – разбавляти solvent -розчинник dissolve - розчиняти surface - поверхня effect - вплив uniform- однаковий

Exercises

1. Answer the questions

1. What is a solution?

2. What is a solute?

3. What is a solvent?

4. What has an effect on the rate of solution?

5. What is solubility?

6. What factors is the solubility determined by?

7. What is a dilute solution?

8. What is a concentrated solution?

9. Is water a solvent?

10. What commonly used solvents do you know?

2. Translate the following sentences:

1. Не proposed to use a new method of collecting data. 2. We had to return the books to the library because we were not allowed to borrow some new ones. 3. We were glad to see them. 4. He wanted the new method to be used in our laboratory. 5. This experiment was not difficult to be carried out in the students' laboratory. 6. We were proud to have been given prizes for our research. 7. Recently they have done a lot of work to investigate the effect concerned. 8. To carry out this experiment is very important. 9. To obtain these results a lot of work had to be done. 10. The experiment to be followed by a discussion was very interesting. 11. The material to be attacked by an acid was placed in a beaker. 12. His article to be referred to later was published last month. 13. D.I. Mendeleyev was the first to arrange the elements according to their atomic masses. 14. The element 101 was the first to have been given the name of a Russian chemist. 15. One of the first man-made elements to be obtained was polonium.