Every time you see molecules, atoms, & particles think of avagadros #. (6.022 x 10^23)
Answer: 13.6 grams of H2O
Solution: (4.56x10^23) x (1 mol H2O/6.022x10^23) x (18 grams H2O/1 mol H2O) = 13.6 grams of H2O
Using dimensional analysis above makes these types of problems easy.
CO₂ + H₂O -------> H₂CO₃
moles of CO₂ =
=
= 11.997 mol
mole ratio of CO₂ : H₂O = 1 : 1
∴ moles of H₂O = (`11.997 mol ) * 1
= 11.997 mol
≈ 12 mol
Mg reaction with O₂ gas will produce MgO so the equation will be
2Mg+O₂⇒2MgO. (You have to find the equation in order two figure out the number of moles of O₂ that will react with 1 mole of MgO).
The first step is to find the number of moles of Mg in 4.03g of Mg. You can do this by dividing 4.03g Mg by its molar mass (which is 24.3g/mol) to get 0.1658mol Mg. Then you have to find the number of moles of O₂ that will react with 0.1658mol Mg. To do this you need to use the fact that 1mol O₂ will react with 2mol Mg (this reatio is from the chemical equation) so you have to multiply 0.1658mol Mg by (1mol O₂)/(2mol Mg) to get 0.0829mol O₂. From here you would usually use PV=nRT and solve for V However, the question tells us that we are at STP, that means you can use the fact that 22.4L of gas is 1 mol of gas at STP. Using that information we can find the volume of O₂ gas by mulitlying 0.0829mol O₂ by 22.4L/mol to get 1.857L which equals 1857mL.
therefore, 1857mL of O₂ gas will react with 4.03g of Mg.
I hope this helps. Let me know in the comments if anything is unclear.
Answer:
i think the answer is B cus i think of that
