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∙ 11y ago10.4 g NaF x 1 mol NaF/42 g x 1 mol F/mol NaF = 0.248 moles F- ions (3 significant figures).
0.277 mole Na2CO3 x 106 g/mole = 29.4 g (to 3 significant figures)
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.
Molar mass NO2 = 46.0 g/mole1.18 g NO2 x 1 mol NO2/46.0 g = 0.0257 moles NO2 (to 3 significant figures)
Since you don't specify the conditions, I will use the current STP. At STP of 0oC (273.15 K for gases) and 100 kPa, the molar volume of a gas is 22.711 L/mol.4.50 mol Cl2 x 22.711 L/mol = 102 L Cl2, rounded to three significant figures.Just in case your teacher is using the older version of STP of 0oC (273.15 K for gases), and 1 atm, the molar volume of a gas would be 22.414 L/mol.4.50 mol Cl2 x 22.414 L/mol = 101 L Cl2, rounded to three significant figures.
4 of them.
6.45 moles X 6.02 X 10 to the 23 power will be right (use 3 significant figures in your answer)
10.4 g NaF x 1 mol NaF/42 g x 1 mol F/mol NaF = 0.248 moles F- ions (3 significant figures).
Cupric sulfate is CuSO4 which has a molar mass of 159.6g/mol. Thus 44.78 g x 1 mol/159.6 g = 0.2806 moles (to 4 significant figures).
The most accurate answer is 0.2 mol/kg.Related Information:The number of significant figures in the final answer must be based on the given with the least number of significant figures which is 2L.
0.277 mole Na2CO3 x 106 g/mole = 29.4 g (to 3 significant figures)
52 g Be x 1 mol/9 g = 5.8 moles (2 significant figures)
(2.7 mol Ca / 1) * (40.078 g Ca / 1 mol Ca) = 108.21 g Ca. After significant figures, the answer is 110 g Ca.
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.
7.20 moles K x 39.1 g/mole = 281.52 g K = 282 g K (to 3 significant figures)
1 mole Cu(NO3)2 = 187.5558g 6.36mol Cu(NO3)2 x 187.5558g/mol = 1190g (rounded to 3 significant figures)
Molarity (M) = moles of solute (mol) / liter of solution (L)M = mol / LYou have 250 mL of Solution, which is250 mL x ( 1 L / 1000 mL ) = ( 250 / 1000 ) L = .25 LSolute is just what's dissolvedSolvent is just what it's being dissolved inSolution is the solute and the solvent.M = mol / LM = 0.65 mol / 0.25 Liters = 2.6 mol/LThe two numbers that you are given, 0.65 moles and 250 mL both have two significant figures, and the answer is two significant figures (2.6 mol/L)Therefore the answer is 2.6 mol/L.