12th Chemistry 9 November 2021 Weekly Revision test solution #pseb _ GAURAV CROOKS PAS test class 12

In a class of 55 students, the number of students studying different subjects are 23 in Mathematics, 24 in Physics, 19 in Chemistry, 12 in Mathematics and Physics, 9 in Mathematics and Chemistry, 7 in Physics and Chemistry and 4 in all the three subjects. Find the number of students who have taken exactly one subject.

The mean and standard deviation of marks obtained by 50 students of a class in there subjects, mathematics, physics and chemistry are given below: Subject Mathematics Physics Chemistry Mean 42 32 40.9 Standard Deviation 12 15 20 Which of the three subjects shows the highest variability in marks and which shows the lowest?

Construct a frequency distribution table for the following marks obtained by 25 students in a history test in class VI of a school: 9,17,12,20,9,18,25,17,19,9,12,9,12,18,17,19,20,25,9,12,17,19,19,20,9 What is the range of marks? What is the highest mark? Which mark is occurring more frequently?

Construct a frequency distribution table for the following marks obtained by 25 students in a history test in class VI of a school: 9,17,12,20,9,18,25,17,19,9,12,9,12,18,17,19,20,25,9,12,17,19,19,20,9 What is the range of marks? What is the highest mark? Which mark is occurring more frequently?

Construct a frequency distribution table for the following marks obtained by 25 students in a history test in class VII of a school: 9,17,12,20,9,18,25,17,19,9,12,9,12,18,17,19,20,25,9,12,17, 19,19,20,9 What is the range of marks? What is the highest mark? Which mark is occurring more frequently?

Air sample from an industrial area of Delhi, which is heavily polluted by CO_(2) , was collected and analysed. One such sample of 224 L of air measured at STP was passed through a 500 " mL of " 0.1 M KOH solution, where CO_(2)(g) was absorbed completely. 50 " mL of " the above solution was then treated with excess of BaCl_(2) solution where all the carbonate was precipitated as BaCO_(4)(s) . The solution was filtered off and the filtrate required 30 " mL of " 0.1 M HCl solution for neutralisation. Q. Calculate the weight of the precipitate of BaCO_(3)(s) obtained from 50 " mL of " the above test solution. (Ba=137,C=12,O=16,Mw(BaCO_(3))=137+12+3xx16=197gmol^(-1))

In a class of 55 students the number of students studying subjects are , 23 iin Mathematics 24.in physics 19in chemisty 12 in Mathematics and physics ,9 in Mathematics and chemistry ,7 in physics and chemistry and 4 in all the three subjects. the number of students who have taken ecactly one subject is

A(C_(6)H_(12))overset(HCl)to underset((C_(6)H_(13)C))(B+C) B overset(alc KOH)toD (isomer of A) D overset("ozonolysis")toE (it gives negative test with Fehling solution but responds to iodoform test). A overset("ozolysis")toF+G (Both give positive Tollen's but do not give iodoform test) F+G overset("conc. NaOH")to HCOONa +a primary alcohol Identify to A to G

In a class test (+ 3) marks are given for every correct answer and (–2) marks are given for every incorrect answer and no marks for not attempting any question. (i) Radhika scored 20 marks. If she has got 12 correct answers, how many questions has she attempted incorrectly? (ii) Mohini scores –5 marks in this test, though she has got 7 correct answers. How many questions has she attempted incorrectly?(iii) Rakesh scores 18 marks by attempting 16 questions. How many questions has he attempted correctly and how many has he attempted incorrectly