Chemistry- urgent!

Perform the following operations and express the results in the correct number of significant digits or decimal places. Express all results in scientific notation. Please help me I'm so confused on how to do this!!

15. (1.71 x 10^6)(6.73 x 10^-8)/2.25 x 10

20. (533)(24)

21. (1.55 x 10^6)(3.05 x 10^-8)^2/(6.53 x 10^-9)^3

22. �ã9.74 x 10-3 + 9.65 x 10-4

  1. 👍 0
  2. 👎 0
  3. 👁 106
  1. You need to know the rules for significant figures. Here is a good site. Study it carefully.

    For 15: All multiplication and division. The s.f. rule is the final answer can have as many s.f. as the LOWEST number involved. All of them are 3 s.f.; therefore, you can have 3 s.f. in the answer. I didn't run the number because I think you omitted a number on the exponent of 10.
    For #20. All multiplication so you can have 2 s.f. as dictated by the 24. My calculator gives 1.2792E4 so this is rounded to 1.3E4.
    For 22:
    In addition and subtraction you are allowed the minimum number after the decimal point, (I don't now what the a squigly line is. I'll assume that is not supposed to be there.
    The first value is the least precise so you can use anything past 0.00001. So we round the final answer to
    0.01070 (and I'm using the rounding rule that says round a 5 to the nearest even number).

    1. 👍 0
    2. 👎 0
    posted by DrBob222

Respond to this Question

First Name

Your Response

Similar Questions

  1. Science (Chemistry)

    2. Perform this operation and report the answer to the correct number of significant figures: What is the mass of a cube of aluminum that is 4.0 cm on each edge? The density of aluminum is 2.7 g/cm^3. Show all calculations leading

    asked by Grace on March 9, 2015
  2. Chemistry

    How you do this? can you do the first one, i'll try the second one if you can explain Perform the following operations and give the answear in standard exponential form with the correct number of significant figures 1) 37.2mL +

    asked by Bryan on January 11, 2007
  3. stats

    Express the following quantities to the correct number of significant figures: (a) 23.043 ± 4.321 (b) 67 ± 9.023 (c) 33.1492934 ± 2 Isn't (a) already the correct number of significant digits? Would (b) be 67.000 ± 9.023? Would

    asked by Sam on October 19, 2008
  4. Chemistry

    It says to perform the following calculations and express your answers in the correct units and number of significant figures. 2.8g/6.86 times 10^-3 l 45.68g +3.8 g 1423 mL - 40mL

    asked by Tangerine on January 27, 2011
  5. Physics

    Talking about significant figures, my Physics textbook lists 5 rules for determining significant figures. 1) All nonzero digits are significant. 2) Zeros to the right of nonzero digits in a number containing a decimal point are

    asked by Autumn on August 21, 2012
  6. Chemistry

    please check my answers for the following questions. 1) when a measurement that has six significant digits is divided by a measurement that has three significant digits, how many significant digits should the answer have? ANSWER:

    asked by anonymous on July 31, 2007
  7. physics

    3. A car speeds up from 10.0 m/s to 30.0 m/s in 3.0 s. What is its acceleration? In your response, show your work, the given and unknown quantities, the equation and any necessary algebra. Express your answer with the correct

    asked by Anonymous on October 16, 2011
  8. Genetics

    β-thalassemia is a human genetic disease that is inherited in an autosomal recessive manner. Individuals with β-thalassemia produce abnormal hemoglobin which results in a reduced ability to carry oxygen in their blood. The

    asked by qwerty on March 27, 2013
  9. Physics

    i have just started physics, can someone please show me step by step how to do this: The radius of Earth is 6 370 000 m. Express this measurement in km in scientific notation with the correct number of significant digits. thank

    asked by y912f on January 28, 2009
  10. Physics

    Calculate the answer for the following question and state the answer with the correct certainty and units. Given the values of b and h, find A. b=3.2 cm, h=10.1 cm A=1/2bh The answer is 16 cm^2, which was rounded to two

    asked by Emily on September 8, 2010

More Similar Questions