Is Matter Around Us Pure? Science - Is Matter Around Us Pure?

The property/ properties which enable copper metal to be used for making electric wires is/ are:

On the basis of composition of matter, milk is considered to be:

“Is malleable and ductile” best describes:

One of the following does not show Tyndall effect. This one is:

You are given a mixture of iodine in alcohol called tincture iodine. Which method will you use to recover both, iodine as well as alcohol, from this mixture?

1. Evaporation.
2. Simple distillation.
3. Fractional distillation.
4. Crystallization.

Which one of the following scrap metal cannot be separated by magnetic separation?

1. Nickel.
2. Cobalt.
3. Chromium.
4. Steel.

Which one of the following is not a metalloid?

1. Boron.
2. Silicon.
3. Gallium.
4. Germanium.

Which one of the following is not a chemical change?

1. Formation of curd.
2. Ripening of banana..
3. Sublimation of naphthalene.
4. Corrosion of photo frame.

Which one of the following is most likely to exhibit Tyndall effect?

1. Sugar and water mixture.
2. Potash alum and water mixture.
3. Chalk powder and water mixture.
4. Potassium permanganate and water mixture.

State whether the following statements are true or false:

1. Bread is an example of solid foam.

2. Sponge is an example of solid sol.

What type of colloids are bread and sponge?

Name one pair of liquids which can be separated by using a separating funnel.

State whether the following statements are true or false: Alcohol can be separated from a mixture of alcohol and water by a separating funnel.

Fill in the following blanks with suitable words:
The three important metalloids are __________ and __________.

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The separation of liquids by fractional distillation is based o the difference in their __________.

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The gases of air can be separated by fractional distillation of liquid air because they have different ___________.

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The elements which are sonorous are called ____________.

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Miscible liquids are separated by __________.

Fill in the following blanks with suitable words: The separation of liquids by fractional distillation is based o the difference in their __________.

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The gases of air can be separated by fractional distillation of liquid air because they have different ___________.

Fill in the following blanks: Milk is a ________ solution but vinegar is a ________ solution.

Fill in the following blanks with suitable words: Miscible liquids are separated by __________.

Fill in the following blanks: A colloid is a _________ mixture and its components can be separated by the technique known as __________.

State whether the following statements are true or false:

1. Bread is an example of solid foam.

2. Sponge is an example of solid sol.

What type of colloids are bread and sponge?

State whether the following statements are true or false:
Alcohol can be separated from a mixture of alcohol and water by a separating funnel.

State whether the following statement is true or false:

Milk is a pure substance.

Name one pair of liquids which can be separated by using a separating funnel.

Name the source from which nitrogen and oxygen are obtained on a large scale.

Name a metal: Which has a low melting point.

What are pure substances? Give two examples of pure substances.

Which of the following contains less solute at a given temperature and pressure?
Unsaturated solution or Saturated solution.

Name the process which can be used to purify an impure sample of copper sulphate.

Whose one of the allotropic forms is a good conductor of electricity. Name the allotrope.

Which type of elements, metals or non-metals, show the property of brittleness?

Which technique is used in a washing machine to squeeze out water from wet clothes while drying?

Which technique can be used to detect and identify traces of poison present in the stomach wash of a person?

Which of the following substances are elements?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine

Define:

1. Solute
2. Solvent

What is a suspension? Give two examples of suspensions.

How will you distinguish a colloid from a solution?

You have been given a suspension and a solution. How could you tell the difference between them by their appearance?

You are given two liquids, one a solution and the other a compound. How will you distinguish the solution from the compound?

Which of the two will scatter light: soap solution or sugar solution? Why?

Which of the following will show Tyndall effect? Why?

1. Salt solution.
2. Starch solution.
3. Milk.
4. Copper sulphate solution.

Which of the following can be separated by using a separating funnel and which cannot be separated by using a separating funnel?

1. Water and kerosene mixture.
2. Water and acetone mixture.

Give reasons for your answer.

How will you separate a mixture of sodium chloride and sand?

How will you separate a mixture of cooking oil (groundnut oil) and water?

Describe a method for separating a mixture of iron filings and sulphur powder other than that by using a magnet.

How is cream separated form milk?

Which method is better for recovering sugar from sugar solution: evaporation or crystallization? Give reason for your answer.

Write a method to separate a mixture of sand and potash alum.

Which method is better for recovering sugar from sugar solution: evaporation or crystallization? Give reason for your answer.

What is meant by (i) elements (ii) compounds, and (iii) mixtures? Write down the names of two elements, two compounds and two mixtures.

What is chromatography? State its two applications.

What are (i) metals (ii) non-metals, and (iii) metalloids? Give two examples each of metals, non-metals and metalloids.

How will you separate a mixture of common salt, sulphur powder and sand?

A mixture contains water, kerosene and sand. How will you separate this mixture?

List five characteristics by which compounds can be distinguished from mixtures.

Give the main differences between physical changes and chemical changes.

How will you separate common salt, sand and iron filings from their mixture?

You are given a mixture of water, groundnut oil and common salt. How will you separate groundnut oil and common salt from it?

With the help of a labelled diagram, describe the method of separating ammonium chloride from a mixture of ammonium chloride and common salt. Mention the difference in the properties of ammonium chloride and sodium chloride which has made this separations possible.

What is fractional distillation? What is the use of fractionating column in fractional distillation?

There is a large group of materials P which can be divided into three groups Q, R, and S on the basis of their properties. The substances belonging to group Q can be solids, liquids or gases. The solids belonging to group Q are usually electrical insulators. Most of the substances of group R are solids which are good conductors of electricity. The substances belonging to group S are neither insulators like Q nor good conductors like R. The properties of S are intermediate between those of Q and R.

1. What could the group of materials P be?
2. Name the substances Q. Give two examples of such substances.
3. Name the substances R. Write two examples of such substances.
4. Name the substances S. Give two examples of such substances.
5. Out of Q, R and S, which substances are malleable and ductile?

There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.

1. What type of substance could X be? Name one substance like X.
2. What type of substance could Y be? Name one substance like Y.
3. What type of substance could Z be? Name one substance like Z.
4. Whish process involves absorption or release of an appreciable amount of energy: formation of substance X or formation of substance Z?
5. Name the three groups into which all the substances like Y are divided on the basis of their properties.