Which explosive substance is obtained, when proportion of dichlorine gas is more in the reaction of dichlorine gas with ammonia gas?

Ammonium chloride and Dinitrogen gas

Write the molecular formula and structural formula of the following substances. (a) Phosphinic acid. (b) Oleum. (c) Perbromic acid.

Hypophosphorous acid is also known as phosphinic acid. Its molecular formula is H 3 PO 2 . Its structure is shown as: Oleum is also known as disulphuric acid or pyrosulphuric acid. Its molecular formula is H 2 S 2 O 7 . Its structure is shown as: Perbromic acid is the most unstable of the halogen(VII) oxoacids. Its molecular formula is HBrO 4 . Its structure is shown as:

Give reason: Fluorine has only - 1 oxidation state, but other halogens have oxidation states as + 1 , + 3 , + 5 and + 7 also.

All halogens exhibit - 1 oxidation state, because they gain an electron to complete their octet structure. Chlorine, bromine and iodine show + 1 , + 3 , + 5 and + 7 oxidation states in different excited states, but fluorine cannot exhibit the higher oxidation states due to the absence of d -subshell, and inability to expand octet structure. Fluorine cannot show + 1 oxidation state also due to high electronegativity.

Give reason: H 2 O is a liquid and H 2 S is a gas.

Water ( H 2 O ) has oxygen as the central atom. Oxygen has smaller size and higher electronegativity as compared to sulphur. Therefore, there is extensive hydrogen bonding in water molecules, which is absent in hydrogen sulphide ( H 2 S ). Molecules of hydrogen sulphide are held together only by weak van der Waal's forces of attraction. Hence, water exists as a liquid while hydrogen sulphide as a gas.

Give reason: BiH 3 is the strongest reducing agent among all the hydrides of Group- 15 elements.

The reducing property increases from NH 3 to BiH 3 . As we move down the group, the size of the element increases and, therefore, the bond length of the M - H bond increases and consequently its dissociation enthalpy decreases, that enables to provide hydrogen more easily. Hence, BiH 3 is the strongest reducing agent among all hydrides of Group- 15 elements.

Write the complete balanced equation for the following: Cl 2 + NaOH hot and con . →

Chlorine reacts with hot and concentrated sodium hydroxide to give sodium chloride, sodium chlorate and water. The reaction is as given below: 3 Cl 2 + 6 NaOH hot and con . → 5 NaCl + NaClO 3 + 3 H 2 O

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter -1 - The p-Block Elements>Gujarat Board-2020>Q 19

EASY

12th Gujarat Board

IMPORTANT

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Which of the following element does not react with oxygen directly?

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Chapter-Wise 3D Chemistry Videos from Embibe Experts EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY

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Sulphur is one of the most useful non-metals which has wide applications in our industries. Watch this video to learn about the important allotropes of sulphur.

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Halogens generally form four kinds of oxoacids, namely, hypohalous acids, halous acids, halic acids and perhalic acids. Let’s delve into the world of oxoacids.

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Reaction of Alcohols With Phosphorus Halides

The reaction of alcohols with phosphorus halides yields an alkyl halide. Let’s watch the video and learn the reaction of alcohols with phosphorus halides.

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