When dividing numbers, the result should have the same number of significant figures as the number with the fewest significant figures in the calculation. Round the final answer to match the least number of significant figures in the original numbers.
The formula unit for magnesium fluoride is MgF2. From the periodic table, add the atomic weight of 1 magnesium atom and 2 fluorine atoms to get to get 62.3018. This means that 1 mole of MgF2 is 62.3018g of MgF2. Now, to find out the mass of 4.78 mol MgF2 X the g/mol so that you will cancel the moles, and keep the grams. 4.78 mol MgF2 X 62.3018g MgF2/1mol MgF2 = 297g MgF2 *The answer 297 is in keeping with significant figures. When you multiply or divide, the answer can have no more than the fewest significant figures in the calculation, which was 4.78, and which has only three significant figures.
To convert atoms of carbon to moles, you need to divide the number of atoms by Avogadro's number, which is (6.022 \times 10^{23}) atoms/mol. Thus, the calculation is: (\frac{5.73 \times 10^{24} \text{ atoms}}{6.022 \times 10^{23} \text{ atoms/mol}} \approx 9.50 \text{ mol}) of carbon.
The number of moles is equal to the mass divided by the molar mass. In mathematical form, it is:Moles = Mass of Mg / Molar Mass of MgMoles = 109.4 / 24.3Moles = 4.501 (rounded to three decimal points)Always keep a Periodic Table handy, molar masses are quite important.
1.00 mole is always 6.022*10+23 particles (of any kind)So divide 3.70*10+23 (electrons) by this number 6.022*10+23 (electrons/mole of electrons) and you'll get the number of moles of electrons.It is 3.70 / 6.022 = 0.614 mole of electrons
To find the number of moles in 1.18 g of NO2, you need to divide the given mass by the molar mass of NO2. The molar mass of NO2 is approximately 46 g/mol. So, 1.18 g / 46 g/mol = roughly 0.026 moles of NO2.
When multiplying or dividing numbers with significant figures, the result should have the same number of significant figures as the factor with the fewest significant figures. Round the final answer to match this rule.
2.264 to 4 significant figures
Significant figures are important for science, they tell how certain you are of a certain value. The rules for significant figures are as follows: If it is a decimal number, look at the first number on the left. If it is not zero, start counting the amount of numbers, and that's how many significant figures you have. For example, 7.495 has 4 significant figures. If it is zero, keep going until there is digit larger than zero, and start counting the numbers until the end. However many numbers there are, that's how many significant figures you have. For example, 0.000331 has 3 significant figures. If the number does not have a decimal, start from the right and if the number is not zero, start counting numbers and that's how many significant figures you have. For example, 93847 has 5 significant figures. If it is zero, the first significant figure will be the first non-zero digit. For example 3873000 has 4 significant figures. When you add or subtract some numbers, the amount of significant figures the answer should be expressed in depends on the number with the least amount of decimal places. For example, 4.398 + 5.2 = 9.6 You express the answer to the lowest number of decimal places a value you are adding or subtracting has. When you multiply or divide numbers, the answer is expressed to the lowest amount of significant figures that the values have. For example: 55 x 7 = 400 (when expressed with correct significant figures)
The basic idea is that the final result should not be - or rather, appear to be - more accurate than the original numbers. Therefore, the final result should not have more significant digits than the original numbers you multiply or divide. For example, if one factor has 3 significant digits, and the other 5, round the final result to 3 significant digits.
3.134
It isn't clear what the question is. If you are supposed to multiply or divide, and if by "signification figures" you mean significant digits, do the multiplication (or division), then round to three significant digits - since the least-precise of the numbers only has three significant digits.
Significant figures are used to receive a more accurate number. To obtain the number you you multiply or divide the quantities, leave as many significant figures in the answer as there are in the quantity with the least number or significant figures. If adding or subtracting quantities, leave the same number of decimal places in the answer as there are in the quantity with the least number of decimal places
Rounded to three significant figures, 0.16/7.252 = 0.0221
Forget about "significant figures"; those are used to determine the precision when you multiply or divide. When adding numbers, the rule is that the result should be rounded according to the precision of the least accurate of the addents. In this case, to one decimal digit.
0.001
When you multiply 16 x 8.02 it equals 128.32, which has 5 significant figures. When you divide 28.58 into 128.32 it gives you 0.223 mL and it needs to be rounded to four significant figures.
The fraction 22/7 is close to PI for four significant digits.