Answer:
a) H2S:SO2 = 2:2 and O2:H2O = 3:2
Explanation:
⇒ H2S:SO2 = 2 mol H2S / 2 mol SO2 ≡ 2 : 2
⇒ O2:H2O = 3 mol O2 / 2 mol H2O ≡ 3 : 2
Answer:
1.35 moles of O²⁻
21.6 grams of O²⁻
Explanation:
We know that the charge on Aluminium ion is +3 (i.e. Al³⁺) while, the charge on Oxide ion is -2 (i.e. O²⁻). Therefore, the overall neutral Al₂O₃ compound has 2 Al³⁺ ions and 3 O²⁻ ions. Since, we can say that,
1 mole of Al₂O3 contains = 3 moles of O²⁻ ions
So,
0.450 moles of Al₂O₃ will have = X g of O²⁻
Solving for X,
X = 0.450 mol × 3 mol ÷ 1 mol
X = 1.35 moles of O²⁻
As the mass of an atom is mainly due to the presence of protons and neutrons hence, the addition of two electrons (-ve 2 shows two gained electron) to Oxygen will make a negligible change to the atomic masss of Oxygen because electron is said to be almost 1800 times lighter than proton. Hence, the ionic mass of O²⁻ will be 16 g/mol and the mass of given moles is calculated as,
Mass = Moles × Ionic Mass
Mass = 1.35 mol × 16 g/mol
Mass = 21.6 g
Answer:
The correct answer is - They gently shake the pan causing the marbles to move back and forth.
Explanation:
When water is heated the molecules present in its liquid state start to move and vibrate faster and allows the water to expand and increase in volume. If the heat is continuously applied to the water its molecules move even faster and escape in the form of molecules of vapor to the atmosphere.
To exhibit this phenomenon by the marble and pan, Richard and Brooke should gently shake the pan causing the marbles to move back and forth which shows faster vibration and movement of molecules.
<u>Answer:</u>
2.07 grams
<u>Explanation:</u>
We know that the molecular mass of 
is 138.205 grams.
In order to find out how many grams we need to make 200 mL having a potassium ion concentration of 0.150, we need to find the number of moles first.
M = moles / liters
0.150 = x / 0.200
x = 0.03 moles
Since there are 2 potassium atoms in each molecule of so we will divide this number by half and multiply it by the molecular mass.
0.03/2 = 0.015 moles
Mass of needed = 0.015 × 138.205 = 2.07 grams
