EASY
JEE Main
IMPORTANT
Earn 100

The number of significant figures in 0.00340 is _________

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Important Questions on Some Basic Concepts of Chemistry

MEDIUM
JEE Main
IMPORTANT
Consider the complete combustion of butane, the amount of butane utilized to produce 72.0 g of water is ______ ×10-1 g. (in nearest integer)
MEDIUM
JEE Main
IMPORTANT
Consider titration of NaOH solution versus 1.25 M oxalic acid solution. At the end point following burette readings were obtained.
(i) 4.5 mL
(ii) 4.5 mL
(iii) 4.4 mL
(iv) 4.4 mL
(v) 4.4 mL
If the volume of oxalic acid taken was 10.0 mL then the molarity of the NaOH solution is ___M. (Rounded-off to the nearest integer)
MEDIUM
JEE Main
IMPORTANT
1.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost during purification. Amount of acetanilide obtained after purification (in g) is ___________ ×10-2.
MEDIUM
JEE Main
IMPORTANT
Methylation of 10 g of benzene gave 9.2 g of toluene. Calculate the percentage yield of toluene (Nearest integer)
EASY
JEE Main
IMPORTANT
4 g equimolar mixture of NaOH and Na2CO3 contains xg of NaOH and yg of Na2CO3. The value of x is g. (Nearest integer)
EASY
JEE Main
IMPORTANT

When 0.15 g of an organic compound was analyzed using Carius method for estimation of bromine, 0.2397 g of AgBr was obtained. The percentage of bromine in the organic compound is _________.(Nearest integer)

[Atomic mass : Silver =108, Bromine =80]

MEDIUM
JEE Main
IMPORTANT
250 mL of 0.5M NaOH was added to 500 mL of 1M HCl. The number of unreacted HCl molecules in the solution after the complete reaction is p×1021. Find out p
(Nearest integer) NA=6.022×1023
MEDIUM
JEE Main
IMPORTANT
The ratio of the mass percentages of  'C & H' and 'C & O' of a saturated acyclic organic compound 'X' are 4:1 and 3:4 respectively. Then, the moles of oxygen gas required for complete combustion of two moles of organic compound 'X' is_______