Answer:
- <em>Hydration number:</em> 4
Explanation:
<u>1) Mass of water in the hydrated compound</u>
Mass of water = Mass of the hydrated sample - mass of the dehydrated compound
Mass of water = 30.7 g - 22.9 g = 7.8 g
<u>2) Number of moles of water</u>
- Number of moles = mass in grams / molar mass
- molar mass of H₂O = 2×1.008 g/mol + 15.999 g*mol = 18.015 g/mol
- Number of moles of H₂O = 7.9 g / 18.015 g/mol = 0.439 mol
<u>3) Number of moles of Strontium nitrate dehydrated, Sr (NO₃)₂</u>
- The mass of strontium nitrate dehydrated is the constant mass obtained after heating = 22.9 g
- Molar mass of Sr (NO₃)₂ : 211.63 g/mol (you can obtain it from a internet or calculate using the atomic masses of each element from a periodic table).
- Number of moles of Sr (NO₃)₂ = 22.9 g / 211.63 g/mol = 0.108 mol
<u>4) Ratio</u>
- 0.439 mol H₂O / 0.108 mol Sr(NO₃)₂ ≈ 4 mol H₂O : 1 mol Sr (NO₃)₂
Which means that the hydration number is 4.
Explanation:
It is the heat required to change a gram of substance from a liquid to a gas.
Answer:
1027.9 mL
Explanation:
Formula P1 x V1 / T1 = P2 x V2 / T2
Fill in what you know
Pressure is constant so no need to put that in making the formula
V1 / T1 = V2 / T2
Voulme 1= 950 mL
Volume 2= ?
Temperature 1 = 25 C
Temperature 2 = 50 C
Explanation:
Formula P1 x V1 / T1 = P2 x V2 / T2
Fill in what you know
Pressure is constant so no need to put that in making the formula
V1 / T1 = V2 / T2
Voulme 1= 950 mL
Volume 2= ?
Temperature 1 = 25 C
Temperature 2 = 50 C
Gravity, its what holds the whole universe together
