First find the moles
moles of the calcium= 72.8 / 40
moles of calcium in 72.8g = 1.82mol
number of atoms= moles x Avogadro constant
atoms = 1.82 x 6.02x10+23
so the number of atoms is 1.096x10+24
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
Answer:
6.97 atm was the equilibrium pressure of HBr .
Explanation:
The value of the equilibrium constant =
Initially:
0 0 7.10 atm
At equilibrium
x x (7.10-2x)
The expression of equilibrium constant can be written as:
Solving for x:
x = 0.065
Partial pressure of HBr at equilibrium :(7.10 - 2 × 0.065) atm = 6.97 atm
6.97 atm was the equilibrium pressure of HBr .
Answer: Ammonium, when heated with aqueous base, will give off NH3 (ammonia) gas, (and depending, water vapor). This will leave the Cr2O3(s). From then on,
it is just adding or subtraction of gases or water vapor. You probably heard “Loss of electrons is Oxidation”, “Gain of Electrons is reduction”. That should help.
Explanation: This isn’t an explanation but an interesting point; Acid-Base and RedOx reactions are useful to the most complex of any Chemistry. Get this down, and Organic Chemistry will be much easier.
Answer:
Potential energy
Explanation:
Potential energy is the energy possed by an object at rest. It is otherwise referred to as the stored energy due position.
