SSC (Marathi Semi-English) १० वीं कक्षा - Maharashtra State Board Important Questions for Science and Technology 1

Observe the following picture a write down the chemical reaction with the explanation.

Write scientific reasons.

Lemon or tamarind is used for cleaning copper vessels turned greenish.

Complete the following flow chart and answer the questions below:

i) In which method pine oil is used?
ii) Explain what method of concentration in brief.

Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
 Reaction on anode region :

`F_e(s) → Fe^(2+) (aq) +2e^-`

 Reaction on anode region :

`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `

When Fe²⁺ ions migrate from anode region they react with ................... to form Fe³⁺ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.

`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `

A way to prevent rusting ..................................................................

Which of the following process to be carried out to avoid the
formation of greenish layer on brass vessels due to corrosion?

Identify the process shown in the diagram and explain it in short

An element has its electron configuration as 2,8,8,2. Now answer the following questions.
a) What is the atomic number of this element?
b) What is the group of this element?
c) To which period does this element belong?

Identify the process given in following passage and draw neat labelled diagram showing the process.
          Electrolysis of molten mixture of alumina (melting point > 2000⁰C) is done in a steel tank. The tank has a graphite lining on the inner side. This lining does the work of a cathode. A set of graphite rods dipped in the molten electrolyte works as anode. Cryolite (Na₃AlF₆) and fluorspar (CaF₂) are added in the mixture to lower its melting point upto 1000⁰C.

Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.

Find the odd man out:

Choose the correct alternative and rewrite the following:

Iron is _____________________.

Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.

Write a short note on Alloying.

Observe the following picture and answer the following questions:

1. What is rust?
2. Write the chemical formula of rust.
3. Write the reaction of oxidation of iron at the anode.
4. Write the reaction of oxidation of iron at the cathode.
5. What is corrosion?

Extraction of moderately reactive elements is done by _______ and _______ method.

Write scientific reason.

On exposure to air, silver articles turn blackish after some time.

Explain the characteristics of ionic compounds.

Complete flow chart given below.

Answer the questions on the following passage.

The minerals from which the metal can be separated economically are called ores. Ores contain many types of impurities such as soil, sand and rocky substances along with metal compounds. These impurities are called gangue.
Metals can be extracted from their ores by means of various methods of separation. The process of extraction of metal in a pure state from the ores is also a part of metallurgy.
Ores are taken out from the mines and the gangue is usually separated from the ore at the site itself by various methods. Then the ores are carried out to the place where metals are produced. Here metals are extracted in pure form. Then metals are further purified by different methods of purification. This entire process is called metallurgy. Most metals being reactive do not occur in nature in the free state but are found in combined state as their salts such as oxides, carbonates, sulphides, and nitrates. however, the most unreactive metals that are not affected by air, water and other natural factors like silver, gold, platinum, generally occur in a free state. The compounds of metals that occur in nature along with the impurities are called minerals.

1. What are ores?
2. Which processes are involved in the branch of metallurgy? What is metallurgy?
3. Which metals are found in a free state?
4. In what forms are metals found in combined state?
5. What is gangue?

Gold plated ornaments is the example of ______.