HSC Science (General) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

How is glucose prepared by commercial method? How is peptide linkage formed?

The half life period of a first order reaction is 6. 0 h . Calculate the rate constant

Arrange the following oxyacids of chlorine in decreasing order of their thermal stability. Give reason.
 HOClO, HOCl, HClO₄, HOClO₂

Write chemical reaction to prepare the following polymer: Teflon

Write chemical reaction to prepare the following polymer :
Nylon - 6

Write the main constituents of dettol.

Write balanced chemical equation for the following :
Action of zinc dust on phenol.

In a first-order reaction A → product, 80% of the given sample of compound decomposes in 40 min. What is the half-life period of the reaction? 

What is the freezing point of a liquid? The freezing point of pure benzene is 278.4 K. Calculate the freezing point of the solution when 2.0 g of a solute having molecular weight 100 g mol^-1
 is added to 100 g of benzene.
( K_f of benzene = 5.12 K kg mol^-1 .) 

How is glucose prepared from starch?

What are racemates?

Answer the following in one or two sentences.

Which of the three types of packing used by metals makes the most efficient use of space and which makes the least efficient use?

Answer the following in one or two sentences.

Mention two properties that are common to both hcp and ccp lattices.

Answer the following in brief.

Calculate the packing efficiency of metal crystal that has simple cubic structure.

Answer the following in brief.

Cesium chloride crystallizes in a cubic unit cell with Cl^– ions at the corners and a Cs⁺ ion in the center of the cube. How many CsCl molecules are there in the unit cell?

Cu crystallizes in fcc unit cell with edge length of 495 pm. What is the radius of Cu atom?

The density of iridium is 22.4 g/cm³. The unit cell of iridium is fcc. Calculate the radius of iridium atom. Molar mass of iridium is 192.2 g/mol.

Aluminium crystallizes in a cubic close-packed structure with a unit cell edge length of 353.6 pm. What is the radius of Al atom? How many unit cells are there in 1.00 cm³ of Al? 

In ionic crystalline solid atoms of element Y form hcp lattice. The atoms of element X occupy one-third of tetrahedral voids. What is the formula of the compound?

An element has a bcc structure with a unit cell edge length of 288 pm. How many unit cells and a number of atoms are present in 200 g of the element? (1.16 × 10²⁴, 2.32 × 10²⁴)