Answer:
5.25g
Explanation:
We'll begin by writing the balanced equation for the reaction. This is shown below:
Na2SiO3 + 8HF → H2SiF6 + 2NaF + 3H2O
From the balanced equation above,
8 moles of HF reacted to produce 2 moles of NaF.
Therefore, 0.5 moles of HF will react to produce = (0.5 x 2)/8 = 0.125 mole of NaF.
Next, we shall convert 0.125 mole of NaF to grams.
This is illustrated below:
Mole of NaF = 0.125 mole
Molar mass of NaF = 23 + 19 = 42g/mol
Mass of NaF =..?
Mass = mole x molar mass
Mass of NaF = 0.125 x 42
Mass of NaF = 5.25g
Therefore, 5.25g of NaF is produced from the reaction.
Basic radicals (cations) have been divided into groups based on Ksp values
Answer:
d. Radon-222
Explanation:
²²⁶₈₈Ra → ²²²₈₆Rn + ⁴₂He
Alpha particle is a helium nucleus with mass number 4 and atomic number 2. According to the law of conversation of mass, the sum of the mass number and atomic number must be equal on both side of the reaction.
Since the mass number of Ra is 226 and that of He is 4. The mass number of the unknown element must be 226 - 4 = 222.
Since the atomic number of Ra is 88 and that of He is 2. The atomic number of the unknown element must be 88 - 2 = 86.
Now looking in the periodic table Radon is the only element with atomic number 86.
Answer:
Zinc Chloride + Difluorine -----> Zinc Fluoride + Dichlorine
Explanation:
ZnCl2 + F2 → ZnF2 + Cl2
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.
