Tag: chemistry

Quizzes (490) Questions (9892)

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 have same significant figures?

  1. $6.02\times 10^{23}$
  2. $7.70\times 10^{-20}$
  3. $7.50$
  4. $0.75$
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

The number of single digits that are important in the coefficient of an expression in scientific notation is termed as significant number.


$(A),(B)$ & $(C)$ have $3$ significant figures.

Wheras, $(D)$ has only $2$ significant figures.

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

Statement I: The number $5,007$ has three significant figures
Because
Statement II: Zeros between non-zero digits are significant

  1. one is True, second is True and currect expilanation

  2. one is true and second is true

  3. one is true and second is False

  4. one is False and second is True

  5. False False
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 Statement I: The number $5,007$ has four significant figures
Because
Statement II: Zeros between non-zero digits are significant
Hence, the statement I is false and statement II is true.

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

Which choice shows the answer to the following mathematical operation with the correct number of significant figures?
$14.5-3.46=$______

  1. $11$
  2. $10$
  3. $11.04$
  4. $11.0$
  5. $11.4$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

      $14.5-3.46=11.04$

In subtraction, the final answer is written as the same number of decimal places as that of the term with the least number of decimal places.
  $\therefore$ The answer is $11.0$

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

Which choice shows the answer to the following mathematical operation with the correct number of significant figures?


$2.8\times 8.96 = ? $

  1. $25.09$
  2. $25.1$
  3. $25$
  4. $25.08$
  5. $25.088$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In multiplication, the final answer is reported as the same number of decimal places as that of the term with the least number of decimal places.


$2.8\times 8.96=25.088=25.1$

Hence, the correct answer is option $B$.

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

Two samples were weighed using different balance and the following data were obtained.
Sample #1=3.719 grams
Sample #2=0.42 gram
The total mass of the samples should be reported as :

  1. 4 grams

  2. 4.1 grams

  3. 4.139 grams

  4. 4.14 grams

  5. 4.140 grams
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

After rounding off to $2$ significant digits, weight of sample $1$ can be reported as $3.72$ grams. Therefore, total mass $= (3.72+0.42)=4.14 $ grams.

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

Which choice shows the answer to the following mathematical operation with the correct number of significant figures?
$\dfrac{12.55}{3.0} =4.18333$

  1. $4.18333$
  2. $4.2$
  3. $4.18$
  4. $4.183$

  5. 37.45
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In multiplication, the final answer is reported as the same number of decimal places as that of the number with the least decimal places.

Therefore, $4.18333$ should be rounded off to only one decimal place.
Therefore, $\dfrac{12.55}{3.0}=4.2$

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

Which choice shows the answer to the following mathematical operation with the correct number of significant figures?
$4.51\times{10}^{5}+3.6\times{10}^{3}$

  1. $4.55\times {10}^{5}$
  2. $8.11\times {10}^{5}$
  3. $4.546\times {10}^{5}$
  4. $8.11\times {10}^{8}$
  5. $4.5\times {10}^{5}$
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

In addition, the final product is reported as the same number of decimal places as that of the number with least decimal places.

$\therefore \quad 4.51\times { 10 }^{ 5 }+3.6\times { 10 }^{ 3 }=4.546\times { 10 }^{ 5 }$
                                                  $=4.5\times 10^5$