Answer:
+43.32 kJ
Explanation:
Step 1: Write the thermochemical equation for the decomposition of sodium nitride
2 Na₃N ⇒ N₂ + 6 Na ΔH = +42.7 kJ
Step 2: Calculate the moles corresponding to 168.4 g of Na₃N
The molar mass of Na₃N is 82.98 g/mol.
168.4 g × 1 mol/82.98 g = 2.029 mol
Step 3: Calculate the heat needed for the decomposition of 2.029 moles of Na₃N
According to the thermochemical equation, 42.7 kJ are required for the decomposition of 2 moles of Na₃N. The heat needed for the decomposition of 2.029 moles of Na₃N is:
2.029 mol × 42.7 kJ/2 mol = 43.32 kJ
Answer:
4per m 2
20 mice divided by 5 so it will be 4 per m 2
Answer:
a. very acidic
Explanation:
A solution with a pH of 1.6 would be described as a very acidic solution.
The pH scale is a convenient scale for expressing the level of acidity or alkalinity of aqueous solutions.
The scale ranges from 1 to 14 in which case 1 is the lower limit and 14 the upper limit.
- An acidic solution has a pH value less than 7. As pH decreases, the acidity of the solution increases.
- Neutral solutions have a pH of 7
- An alkaline solution has a pH greater than 7 and the level of alkalinity increases as pH increases.
This corresponds to the law of multiple proportions which states that when a certain amount of compound reacts to form another compound, the ratio of the amounts between the reactants and the products are a fraction of simple or whole numbers.<span />