CBSE science
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Write the name formula of the first member of the carbon compounds having functional group-CHO.
The first member of the carbon family having the functional group-CHO is methanal. A formula of methanal HCHO.
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Write the name and formula of a molecule made up of three atoms of oxygen.
Ozone (O3).
Why do all the elements of the (a)same group have similar properties, (b) same period have different properties.
a) Elements in the same group have similar properties because they have the same number of valence electrons in their outermost shell.
b) Elements in the same period have different properties because the number of valence electrons in their outermost shells differ.
An element E has following electronic configuration.
K L M
2 8 6
a) To which period of the periodic table does element E belong?
b) To which group of the periodic table does element E belong?
c)State the number of valence electrons present in element E.
d) State the valency of the element E.
(a) The element E belongs to group 16.
(b) The element E belongs to the 3rd period.
(c) The element E has 6 valence electrons
(d) The element E has a valence of +6 or -2.
Name the oxidizing agent used for the conversion of ethanol to ethanoic acid. Distinguish between ethanol and ethanoic acid on the basis of (i) litmus test,(ii) reaction with sodium hydrogen carbonate.
Alkaline potassium permanganate KMnO4 can be used as an oxidising agent for a conversion of ethanol to ethanoic acid. Oxidising agent for the conversion of ethanol to ethanoic acid.
i) Litmus test:
Ethanoic acid changes blue litmus paper to red.whereas ethanol does not change the colour of litmus paper.
ii) sodium hydrogen carbonate NaHCO3 Test:
Ethanoic acid reacts with sodium hydrogen carbonate give brisk effervescence with the liberation of carbon dioxide gas which turns lime water milky.
Ethanol does not give this test.
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Mock Test Series
Mock Test Series