Answer:
154 g
Explanation:
Step 1: Write the balanced decomposition equation
2 NaN₃(s) ⇒ 2 Na(s) + 3 N₂(g)
Step 2: Calculate the moles corresponding to 79.5 L of N₂ at STP
At STP, 1 mole of N₂ occupies 22.4 L.
79.5 L × 1 mol/22.4 L = 3.55 mol
Step 3: Calculate the number of moles of NaN₃ needed to form 3.55 moles of N₂
The molar ratio of NaN₃ to N₂ is 2:3. The moles of NaN₃ needed are 2/3 × 3.55 mol = 2.37 mol.
Step 4: Calculate the mass corresponding to 2.37 moles of NaN₃
The molar mass of NaN₃ is 65.01 g/mol.
2.37 mol × 65.01 g/mol = 154 g
Explanation:
Entropy refers to the degree of disorderliness of system. Basically it refers to how random a system is.
Gong through the options.
A. The phase change is from solid to liquid. Liquid has a greater degree of disorderliness compared to solid hence entropy is increasing.
B. The phase change is from solid to gas. Gas particles has a greater degree of disorderliness compared to solid hence entropy is increasing.
C. The phase change is from aqueous to liquid. Aqueous solutions has a greater degree of disorderliness compared to liquid hence entropy is decreasing.
D. The reactant side has; solid + gas. In the product side, there is only gas. The product side has a greater degree of disorderliness hence the entropy is increasing.
E. The entropy of the product is greater than the entropy of the reactants hence entropy is increasing.
F. The phase change is from aqueous to solid. Aqueous solutions has a greater degree of disorderliness compared to solid hence entropy is decreasing.
B
Explanation:
I rember when I learned this in 3rd grade
Answer:
See below
Step-by-step explanation:
heat gained by metal + heat lost by water = 0
m₁C₁ΔT₁ + m₂C₂ΔT₂ = 0
C₁ = -(m₂C₂ΔT₂)/(m₁ΔT₁)
The factors determining C₁ are
- mass of water
- temperature change of water (T_f - Ti)
- mass of metal
- temperature change of metal (T_f - Ti)
Any factor that makes the numerator higher or the denominator lower than what you thought, will give a calculated C₁ that is too high (and vice versa).
The major sources of uncertainty are probably in determining the temperatures, especially the initial and final temperatures of the metal. However, you will have to decide what the principal factors were in your experiment.
For example, did the metal have a chance to cool during the transfer to the calorimeter? How easy was it to determine the equilibrium temperature, etc?
Factors Affecting the Calculation of Specific Heat Capacity
<u> Too Low </u> <u> Too high </u>
Water Water
Mass less than thought Mass more than thought
Ti lower Ti higher
T_f higher T_f lower
Metal Metal
Mass more than thought Mass less than thought
Ti higher Ti lower
. Iron is divalent to hydrogen and water.
