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For this you need the Atomic Mass of He. Take the number of grams and divide it by the atomic mass. Multiply by one mole for units to cancel.

75.0 grams He / (4.00 grams) = 18.8 moles He

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How many grams are in 0.75 moles of SO2?

To convert moles to grams, you need to use the molar mass of the compound. The molar mass of SO2 is approximately 64.07 g/mol. Multiplying the number of moles by the molar mass gives: 0.75 moles x 64.07 g/mol = 48.0525 grams of SO2.


Convert 125 grams of calcium to moles?

For this you need the atomic mass of Ca. Take the number of grams and divide it by the atomic mass. Multiply by one mole for units to cancel.125 grams Ca / (40.1 grams) = 3.12 moles Ca


How many atoms are contained in 6.75 moles of C2H6?

6.02 X 1023 particles per mole X .75 moles = 4.52 X 1023 molecules.


How many hydrogen atoms are present in 75.0 of g H2O?

The gram-molecular mass of H2O is 18.01. Therefore, 75.0 grams contains 75.0/18.01 = 4.16 moles. Each molecule contains two hydrogen atoms. Therefore, the number of hydrogen atoms = 2(4.16)(6.022 X 1023) = 5.01 X 1024 atoms.


How many moles of hydroxide ion are there in a 250 mL sample of 5.00 M solution of sodium hydroxide?

n=c/v n=3M/.25L n=12 mol m=Mxn m=58.443 g/mol x 12 mol m=701.3 g n= mol c=concentration v=volume m=mass M= molar mass Tylerops: I don't agree with this answer. Molarity is defined as Moles/Liters. In other words Molarity is the concentration of a solution. In the above n= Concentration / Liters. That is equal to saying Moles=(Moles/liters)/ Liters. In the above question the concentration is (3 moles/ liter), or 3M. Plus, how can it be possible to have 12 moles in 250ml when you only have 3 moles in each liter of the original solution? Correct ANSWER: 3.00 M, or 3 moles per (L) "liter" calls for having 3 moles per liter of the solution. The question asks how many moles must be in 250ml of a solution that has 3 moles per Liter. You must ask yourself what percent of 1 Liter is 250mls? Since there are a thousand ml in one liter, (1000ml=1L), then 250ml is exactly 25% of a Liter, or .25L. So, 250ml can only hold 25% of the 3.00 Molarity. Meaning that you multiply 3 x .25 and get .75 moles. 58.443g/molNaCl x .75 moles = FINAL ANSWER 43.83225g NaCl, Sig Fig, 43.83gNaCl