Advertisements
Advertisements
प्रश्न
Find the odd man out:
Camphor, Ammonium Chloride, Naphthalene balls, Sugar
उत्तर
Sugar
Camphor, ammonium chloride, naphthalene balls are volatile, while sugar is a non-volatile substance.
APPEARS IN
संबंधित प्रश्न
When crystals of copper sulphate are strongly heated, the residue obtained is ___________.
(A) red in colour
(B) blue in colour
(C) green in colour
(D) colourless
What happens chemically when quicklime is added to water filled in a bucket?
One of the following is an endothermic reaction. This is:
(a) combination of carbon and oxygen to form carbon monoxide
(b) combination of nitrogen and oxygen to form nitrogen monoxide
(c) combination of glucose and oxygen to form carbon dioxide and water
(d) combination of zinc and hydrochloric acid to form zinc chloride and hydrogen
What type of reaction is represented by the following equation?
CaO + H2O → Ca(OH)
What type of reaction is represented by the following equation?
2 Ca + O2 → 2CaO
What type of chemical reaction take place when a magnesium wire is burnt in air?
What type of chemical reaction is represented by the following equation?
A + B → C
Define a combination reaction.
Consider the following equation of the chemical reaction of a metal M:
4M + 3O2 → 2M2O3
This equation represents:
(a) combination reaction as well as reduction reaction
(b) decomposition reaction as well as oxidation reaction
(c) oxidation reaction as well as displacement reaction
(d) combination reaction as well as oxidation reaction
When hydrogen burns in oxygen, water is formed and when water is electrolysed, then hydrogen and oxygen are produced. What type of reaction takes place:
(a) in the first case?
(b) in the second case
What happens during a chemical reaction ?
What do you understand by a chemical bond ?
Fill in the blank
A reaction in which two or more substances combine to form a single substance is called a ............ reaction.
Fill in the blank
The chemical reaction between hydrogen and chlorine is a ................ reaction
Explain the following type of chemical reaction, giving two examples for it:
Combination reaction
A student prepared an aqueous solution of CuSO4 in beaker X and an aqueous solution of FeSO4 in beaker Y. He then dropped some iron pieces in beaker X and some zinc pieces in beaker Y. After about 10 hours he observed that the solutions in X and Y respectively appear:
(A) blue and green
(B) colourless and pale green
(C) colourless and light blue
(D) greenish and colourless
Explain the terms with examples.
Combination reaction
(a) What is double displacement reaction? Explain with an example.
(b) A small amount of quick lime is added to water in a beaker.
(i) Name and define the type of reaction that has taken place.
(ii) Write balanced chemical equation for the above reaction and the chemical name of the product formed.
(iii) List two main observations of this reaction.
Define: Chemical combination reaction
Classify the following reaction into different type:
CaO(s) + H2O(l) → Ca(OH)2(aq)
State why a direct combination reaction is called a – ‘synthesis reaction’.
Classify the following reaction into –
- Direct combination
- Decomposition
- Displacement
- Double decomposition
The reaction is – Molten zinc at high temperatures, burns in air to give zinc oxide.
Select the correct answer for the statement given below:
The product formed during direct combination reaction of carbon dioxide and water.
Complete the statement by filling in the blank with the correct word:
Direct combination reaction of phosphorus pentoxide with water gives _______.
Give a balanced equation for the following type of reaction:
A reaction of direct combination i.e. synthesis in which twp gases combine to give another gas – which turns lime water milky.
Which changes occur during chemical changes?
H2(g) + Cl29(g) → 2HCl(g) is a ______
The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy is a kind of:
Identify the types of chemical reactions occurring during the combustion of fuel:
Balance the following chemical equation and identify the type of chemical reaction.
`"Mg"("s") + "Cl"_2("g") -> "MgCl"_2("s")`
Balance the following chemical equation and identify the type of chemical reaction.
`"Na"("s") + "S"("s") overset("(Fuse)")(->) "Na"_2"S"("s")`
Balance the following chemical equation and identify the type of chemical reaction.
`"CaO"("s") + "SiO"_2("s") -> "CaSio"_3("s")`
Give the chemical reaction when a few pieces of slaked lime are added to a beaker half-filled with water. Will it be an endothermic or exothermic reaction?
Read the text below and answer the questions that follow:
A small amount of hydrochloric acid was taken in a test tube. The test tube was heated. A glass rod was dipped in the ammonia solution and held on the top of the test tube. A white smoke was seen emanating from the tip of the glass rod.
- What must have happened?
- Which colour of gas is formed?
- Write the chemical equation for the reaction.
- Assertion: Rusting of Iron is endothermic in nature.
- Reason: As the reaction is slow, the release of heat is barely evident.
