Chemical Formula & Reactions-1

Which of the following statements is wrong about chemical formula?

• Kinds of elements
• Number of atoms
• Kind of reaction
• Combination ratio

What you can predict about the HNO₃ ?

• There is only one hydrogen atom
• There is only one nitrogen atom
• There are three oxygen atoms
• There are three atoms

Which of the followings formulas contains 4 different kinds of elements?

• KMnO₄
• (NH₄)₂Cr₂O₇
• H₂SO₄
• CH₃COOH

How many atoms are there in CaCO₃

• 5
• 4
• 3
• 2

Which of the following formulas 8 oxygen atoms?

• Mg(NO₃)₂
• H₂CO₃
• Ca₃(PO₄)₂
• (NH₄)₂SO₄

Which of the following changes is chemical change?

• Rotting apple
• Melting ice
• Breaking glass
• Dissolving salt

Which of the following evidences shows that chemical change is taking place? 

• Change in color of substance
• Formation of new substance 
• Change in size of substance
• Formation of new mixture

What are the substances that underwent chemical change?

• Chemicals
• Products
• Reactants
• Reactions

What are the coefficients of the following reaction?
... NH_3(aq)  + ...O_2(g) → ...NO_(g) + ...H₂O_(l) 

• 2,3,2,3
• 4,5,4,6
• 1,3,1,2
• 4,5,4,5

What is the missing chemical formula in following reaction?
6..... + 6H₂O → C₆H₁₂O₆ + 6O₂

• CO₂
• CO
• H₂O₂
• CH₄