Q1.4CYL - Chemistry (OpenStax)

Question

(a) Add 2.334 ml. and 0.31 ml.

(b) Subtract 55.8752 m from 56.533 m.

Step-by-Step Solution

Answer

      a).     After addition Result= 2.64mL

          Round to 2.64mL  Rund to hundred places; Two decimal places)      

 

      b).      After subtraction Result =0.6578m 

  Round to 0.658m (Round to thousand places; Three decimal places)

Step1: Significant figures

All of the digits in measurement, including the uncertain last digit, are called significant figures or significant digits.

Note that zero may be a measured value; for example, if you stand on a scale that shows weight to the nearest pound and it shows "120," then the 1 (hundreds), 2 (tens) and 0 (ones) are all significant (measured) values.

 

Step 2: Rules used to determine Significant figures in addition and subtraction

• Count the number of significant figures in the decimal portion ONLY of each number in the problem.
• Add or subtract in the normal fashion.
• Your final answer may have no more significant figures to the right of the decimal than the LEAST number of significant figures in any number in the problem.

Step 3: Addition and subtraction

      a).     2.334 mL + 0.31 mL

              =2.644mL

          Answer  = 2.64mL

          Round to 2.64mL 

          Round to hundred places; Two decimal   places)      

 

      b).      56.533m - 55.8752m

                          =   00.6578m 

          Answer   =0.658m

          Round to 0.658m

          Round to thousand places; Three  decimal places)