Prepare Yourself for UP Board Class 10 Science Subject through this Practice Paper
News DeskUpdated Sun, 27 Jan 2019 04:51 PM IST
UP Board Class 10th Science: Model papers are being provided here for a thorough revision. Science is one of the most important subjects for class 10th students of UP. Therefore, students should prepare this for sure. The sample paper is given here along with the tips which are very useful for students of the UP Board of Examination, Class 10th.
The sample paper is especially being prepared for the students by the experts. Practising these questions will hopefully give a positive result.
Q 1: Define a balanced chemical equation? Explain why should chemical equation is balanced?
A chemical equation in which the total numbers of atoms of each element is the same in both sides i.e., reactants and products, is called a balanced chemical equation.
For example: When potassium chlorate is heated potassium chloride and oxygen are formed. (Give equation)
The numbers of different elements present in products and reactants are as given ahead:
No. of atoms of elements: K
In reactants: 2
In products: 2
No. of atoms of elements: Cl
In reactants: 2
In products: 2
No. of atoms of elements: O
In reactants: 6
In products: 6
From the dove table, the number of atoms in each element in reactants and products is equal so given chemical equation is balanced.
Q2. While diluting an acid, why is it recommended that the acid should be added to water to acid?
Since the process of dissolving an acid in water is exothermic, it is always recommended that acid should be added to water. If it is done the other way it is possible that because of the large amount of heat generated the mixture splashes out and causes burn.
Q 3: Define Metallurgy. Explain the various steps involved in metallurgy.
Metallurgy: The various processes involved in the extraction of metals from their ores and refining is known as metallurgy. Various physical and chemical processes are employed to obtain a pure metal depending on the properties of metal and impurities present in it. It is not possible to extract all metals from their ores using one common method, although the steps involved in the extraction of all metals have been broadly classified in their main procedure:
- Concentration or enrichment of ore.
- Conversion of the concentrated ore into metal oxide.
- Refining (purification) of impure metal.
The concentration of Ore: large lumps of the ore are broken into smaller pieces. Which are further finely grind.
The ore has impurities like sand, dust, stones, lime, mud, etc. These impurities are collectively called gangue or matrix. Removing the gangue to obtain grounded ore with a higher percentage of metal is called concentration of ore. Depending on the nature of the ore gangue, any of the undermentioned physical methods is employed to concentrate the ores.
Explain further with examples of Gravity separation method, magnetic separation, Froth floatation process and more.
Q 4. How will you obtain ethane from methane (write chemical equation only)
(Write chemical equation)
Q 5. What is the main difference between Mendeleef’s periodic law and modern periodic law?
Ans. According to Mendeleef’s periodic law, the chemical and physical properties of an element are the periodic function of the atomic mass, whereas according to modern periodic law the chemical and physical properties of an element are the periodic function of their atomic numbers.
Q 6. Differentiate between androecium and gynoecium.
Ans. The male parts (stamens) of a flower are collectively known as androecium. Stamens produce pollen grains in another part.
The female part of a flower is called gynoecium. It is made of one or more carpels. Ovules are formed in ovum part of the carpel.
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