Tag: chemistry

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Questions Related to chemistry

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

Which of the following values possess maximum number of significent zeros?

  1. $0.00007$
  2. $0.00070$
  3. $20.000$
  4. $0.800$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Count significant zeros (zeros that count as significant figures): 0.00007 has 0, 0.00070 has 1, 20.000 has 3, 0.800 has 2. Option C has the maximum significant zeros (3 trailing zeros after decimal).

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

Which among the following measurements contains the highest number of significant figures? 

  1. $1.123 \times 10^{-3}kg$
  2. $1.2 \times 10^{-3}kg$
  3. $0.123 \times 10^{3}kg$
  4. $2 \times 10^{5}kg$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option A has 4 significant figures (1.123). Option B has 2 (1.2). Option C has 3 (0.123). Option D has 1 (2).

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

The correctly reported answer of the addition of 4.523, 2.3 and 6.24 will have significant figures

  1. 2

  2. 3

  3. 4

  4. 5
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When adding numbers, the result should be rounded to the same number of decimal places as the term with the fewest decimal places. Adding 4.523, 2.3, and 6.24 yields 13.063. Since 2.3 has only one decimal place, the sum must be rounded to one decimal place, giving 13.1, which contains 3 significant figures.

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

Number of significant figures in $ 2000\times 10^2$ is ____ .

  1. 6

  2. 1

  3. 4

  4. Infinite
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the number 2000 x 10^2, the trailing zeros without a decimal point are generally considered ambiguous, but following standard rules for scientific notation conversion or explicit digits, 2000 written without a decimal point has only 1 significant figure (the leading 2), as the zeros are placeholders.

Multiple choice chemistry measurement and data processing and analysis uncertainties and errors, graphical techniques uncertainty in measurement measurement of properties

Which of the following has two significant figures?

  1. $0.070$
  2. $0.70$
  3. $7.0$
  4. $70$
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation


Leading Zeroes are not significant because these zeroes only serve as space holder. They are there to put decimal point in correct location. Trailing zeroes in a number containing decimal point are significant.

Leading zeroes in whole number are never significant so 70 has only 1 significant figure.

So, option A, B and C are correct.