Guess and check, test, trial and error, completion.
Double displacement reactions are when the cations and anions of 2 compounds are exchanged. Cation of one reactant will form a new product with the anion of the other reactant and vice versa.
MgCl₂ --> Mg²⁺ + 2Cl⁻
Na₂CO₃ --> 2Na⁺ + CO₃²⁻
the cations and anions are exchanged therefore double displacement reaction is as follows;
MgCl₂(aq) + Na₂CO₃(aq) --> MgCO₃(s) + 2NaCl(aq)
Answer:
the partial pressure of Xe is 452.4 mmHg
Explanation:
Dalton's law of partial pressures says that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
The partial pressures can be calculated with the molar fraction of the gas, in this case, Xe.
Molar fraction of Xe is calculated as follows:


Then, 0.29 is the molar fraction of Xe in the mixture of gases given.
To know the parcial pressure of Xe, we have to multiply the molar fraction by the total pressure:
Partial Pressure of Xe=1560mmHg*0.29
Partial Pressure of Xe=452.4mmHg
Answer:
C. 4x10⁻⁴ mol / (Ls)
Explanation:
Based in the reaction:
5 H₂O₂(aq) + 2 MnO₄⁻(aq) + 6 H⁺(aq) → 2 Mn²⁺(aq) + 8 H₂O(l) + 5 O₂(g)
2 moles of MnO₄⁻ disappears while 5 moles of O₂ appears.
If 5 moles appears in a rate of 1.0x10⁻³mol /(Ls), 2 moles will disappear:
2 moles ₓ (1.0x10⁻³mol /(Ls) / 5 moles) = <em>4x10⁻⁴ mol / (Ls)</em>
Right answer is:
C. 4x10⁻⁴ mol / (Ls)
The moles of potassium that you would need to prepare 1200 g of 5% potassium sulfate solution is 1.538 moles
calculation
calculate the mass potassium using the below formula
%M/M = mass of the solute(potassium)/mass of the solvent (potassium sulfate solution)
let the mass of potassium be represented by Y
then convert % into fraction = 5/100
5/100 = Y/1200
cross multiplication
100y = 6000
divide both side by 100
Y= 60 g
moles of potassium =mass/molar mass
= 60/39=1.538