Hello!
To find the mass of helium, we need to multiply the total moles by the mass of helium. We are given 2.714 moles of helium, and the mass of helium is about 4.00 grams. Now, we multiply the two values together to get the grams.
2.714 moles x 4.00 grams = 10.856 grams
According to the number of significant figures, 2.714 moles of helium has a mass of 10.9 grams (exact value: 10.856 grams).
B) land cools off much faster than water (creating a air region of high density above land and lower density above sea)
Answer:
convert 250.0 mL in Liters :250. 0 / 1000 = 0,25 LDensity = 1.240 g/LMass
Explanation:
Sorry I don’t get the question Buh I’m sure you’ll get it eventually
The balanced reaction is
Na2O + H2O --> 2NaOH
If 2.24 moles of sodium oxide react, that means 4.48 moles of NaOH is formed as it is a 1 to 2 stoichiometric relationship.
Now we multiply by the molar mass to get grams.
4.48 moles NaOH * (39.997 grams/1 mole) = 179.2 grams
Your answer is 179. grams.
