Answer:
Calcium can be ignited and will when burning react with both oxygen and nitrogen forming calcium oxide, CaO, and calcium nitride, Ca3N2.
Answer: E. It decreases the value of Eact.
Explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.
Answer:
Mass = 2.355 g
Explanation:
Given data:
Mass of K₂O needed = ?
Mass of KNO₃ produced = 5.00 g
Solution:
Chemical equation:
K₂O + Ca(NO₃)₂ → CaO + 2KNO₃
Number of moles of KNO₃:
Number of moles = mass/molar mass
Number of moles = 5.00 g/ 101.1 g/mol
Number of moles = 0.05 mol
now we will compare the moles of KNO₃ and K₂O.
KNO₃ : K₂O
2 : 1
0.05 : 1/2×0.05 = 0.025 mol
Mass of potassium oxide needed in gram:
Mass = number of moles × molar mass
Mass = 0.025 mol × 94.2 g/mol
Mass = 2.355 g
Answer:
11.2 M → [HCl]
Explanation:
Solution density = Solution mass / Solution volume
35.38 % by mass, is the same to say 35.38 g of solute in 100 g of solution.
Let's determine the moles of our solute, HCl
35.38 g . 1 mol/36.45 g = 0.970 moles
Let's replace the data in solution density formula
1.161 g/mL = 100 g / Solution volume
Solution volume = 100 g / 1.161 g/mL → 86.1 mL
Let's convert the volume to L → 86.1 mL . 1L / 1000 mL = 0.0861 L
Molarity (M) → mol/L = 0.970 mol / 0.0861 L → 11.2 M
Answer:
Percent by mass is calculated by tihis formula, Mass of solute (g) ÷ mass of solution (g)] × 100.
Explanation:
For example: if you have a solution 45% m/m (mass percentege), you have 45 g of solute in 100 g of solution.
