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Chemical formula

Example: Balanced Chemical Equations with Subscripts Water: $$\ce{H2O}$$ Carbon dioxide: $$\ce{CO2}$$ Iron(III) hydroxide (Rust reaction): $$\ce{4Fe + 3O2 + 6H2O -> 4Fe(OH)3}$$ Copper(II) sulfate pentahydrate: $$\ce{CuSO4 * 5H2O}$$ Chemical Formulas in Chemistry Chemical formulas are the symbolic representations of chemical substances. They show the elements present in a compound and the ratio in which the atoms of these elements combine. Chemical formulas are essential for understanding the composition, structure, and behavior of compounds in chemical reactions. 1. What is a Chemical Formula? A chemical formula uses symbols of elements and numerical subscripts to represent the composition of a substance. For example, the formula for water is: $$ \ce{H2O} $$ This indicates that each water molecule is made up of 2 atoms of hydrogen and 1 atom of oxygen. 2. Types of Chemical Formulas Empirical Formula Molecular Formula Structural Formula...

IIT MCQ

1. Two spherical block bodies A and B are emitting radiations at same rate . The radius of B is doubled keeping radius of A fixed . The wavelength corresponding to maximum intensity becomes half for A , while it remains same for B . Then , the ratio of rate of radiation energy emitted by A and B is : 

(a) 2
(b) 1/2
(c) 4
(c) 1/4 

Answer: (c) 

2. Amino acids are : 
 
(a) Acidic 
(b) Amphoteric
(c) Basic 
(d) Neutral 

Answer: amphoteric  

3. Area bounded by the curve y = x^3 , the x axis and the ordinates x= -2 and x = 1 , is 

 (a) -9 
 (b) -15/14
 (c) 15/14
 (d) 17/4 

Answer : (d) 

4. Four point charges q , -q , Q and 2Q are placed in order at the corners A ,B , C and D of a square . If the field at the mid point of CD is Zero then the value of q/Q is : 

 (a) 1
 (b) 5/√2
 (c) 2√2/5
 (d) 5√5/2

Answer : (d) 

5. The linkage which holds various amino acid units in primary structures of proteins 

 (a) Glycoside linkage 
 (b) Peptide linkage 
 (c) Ionic linkage 
 (d) Hydrogen bond 

Answer : (b) 

6. Maltose on hydrolysis gives 
 
 (a) alpha -D- glucose 
 (b) alpha and beta -D- glucose 
 (c) Glucose and fructose 
 (d) Fructose only 

Answer : alpha -D- glucose 

7. 5 kg of ice at -10°C are added to 5 kg of water at 10°C . The temperature of resulting mixture is : 

 (a) 0°C 
 (b) -2°C 
 (c) 4°C 
 (d) 2°C 

Answer : (a) 

8. The area enclosed within the curve |x| + |y| = 1 is 

 (a) √2 
 (b) 2
 (c) 2√2 
 (d) 4 

Answer : (b) 

9. The area between the curve y = 2x^4 - x^2 , the x axis and the ordinates of two minimum of the curve is 

(a) 7/120 
(b) 9/120
(c) 11/120
(d) None of these 

Answer : (a) 

10. At equilibrium the rate of dissolution of a solid solute in a volatile liquid solvent is ...... 

(a) less than the rate of crystallization 
(b) greater than the rate of crystallization 
(c) equal to the rate of crystallization 
(d) Zero 

Answer : (c) 

11. If x = a sin[ wt + π/6 ] and x' = a coswt , then what is the phase difference between the two waves ? 

(a) π/3
(b) π/6 
(c) π/2
(d) π 

Answer: (a) 

12. If the maximum speed of a particle on a travelling wave is Vo , then find the speed of a particle when the displacement is half of the maximum value .

(a) Vo/2
(b) √3Vo/4
(c) √3Vo/2
(d) Vo 

Answer : (c) 







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