Percentage of calcium in calcium carbonate is___________________?
A. 80%
B. 30%
C. 40%
D. 20%
Chemistry Basic Concept
How many isotopes have odd atomic number ?
How many isotopes have odd atomic number ?
A. 154
B. 280
C. 86
D. 300
The number of moles of CO2 which contains 16 g of oxygen is__________________?
The number of moles of CO2 which contains 16 g of oxygen is__________________?
A. 0.25
B. 0.5
C. 0.75
D. 1
The volume occupied by 2.8 g of N2 at STP______________________?
The volume occupied by 2.8 g of N2 at STP______________________?
A. 2.24 dm3
B. 22.4 dm3
C. 1.12 dm3
D. 112 dm3
Which one of the following has the maximum number of isotopes ?
Which one of the following has the maximum number of isotopes ?
A. oxygen
B. carbon
C. tin
D. chlorine
moles of each aluminium and oxygen react with each other to produce aluminium oxide. The amount of product formed is______________________?
moles of each aluminium and oxygen react with each other to produce aluminium oxide. The amount of product formed is______________________?
A. 0.18 mole
B. 0.27 mole
C. 0.24 mole
D. 0.09 mole
Which of the following terms is not used for ionic compound ?
Which of the following terms is not used for ionic compound ?
A. formula unit
B. empirical formula
C. molecular formula
D. formula mass
The number of isotopes of elements with even mass number and even atomic number are ________________?
The number of isotopes of elements with even mass number and even atomic number are ________________?
A. 280
B. 300
C. 154
D. 54
One mole of CO2 contains?
One mole of CO2 contains?
A. 6.022 x 1023 atoms of oxygen
B. 22-gram electrons
C. 6.022 x 1023 atms of carbon
D. both B. & C.
Which of the following statements about isotopes is correct ?
Which of the following statements about isotopes is correct ?
A. Isotopes with odd atomic number are abundant
B. Isotopes with odd atomic number and even mass number are abundant
C. Isotopes with even atomic number and even mass number are abundant
D. Isotopes with even atomic number and odd mass no are abundant