Std-10 Most Imp Ch 8 Gseb L-7

In a Std. X class, out of 40 students, 10 students use spectacles, 2 students have positive power and 8 students have negative power and 8 students have negative power of lenses in their spectacles . Generally which type of spectacles do most of the students use ?

What is the pH of 7.0 xx 10^(-8)M acetic acid. What is the concentration of un-ionsed acetic acid. K_(a) of CH_(3)COOH = 1.8 xx 10^(-5) .

List two most common STDs.

Most common bacterial STD is:

If l=LCM of 8!,10! and 12! and h=HCF of of 8!,10! and 12! then (l)/(h) is equal to

The arrangement of rational numbers (-7)/(10),(5)/(-8),(2)/(-3) in ascending order is (2)/(-3),(5)/(-8),(-7)/(10) (b) (5)/(-8),(-7)/(10),(2)/(-3) (c) (-7)/(10),(5)/(-8),(2)/(-3)(d)(-7)/(10),(2)/(-3),(5)/(-8)

Calculate the change in pH if 0.02 mol CH_(3)COONa is added to 1.0L of this solution. ltbRgt K_(a) of CH_(3)COOH = 1.8 xx 10^(-5) .