Answer:
1.66 * 10^-23 moles
Explanation:
If you follow dimensional analysis, molecules to moles is 10 molecules divided by 6.022 times 10 to the 23rd and that gives you your answer
N=9.933
Explanation:
no of mole = m÷mr
then ,no of molecules=n×la
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:
0.214 L
Explanation:
Step 1: Write the balanced equation
This is a single displacement reaction.
Zn(s) + 2 HCl(aq) ⇒ ZnCl₂(aq) + H₂(g)
Step 2: Calculate the moles corresponding to 0.625 g of Zn
The molar mass of Zn is 65.38 g/mol.
0.625 g × 1 mol/65.38 g = 9.56 × 10⁻³ mol
Step 3: Calculate the moles of H₂ produced from 9.56 × 10⁻³ moles of Zn
The molar ratio of Zn to H₂ is 1:1. The moles of H₂ produced are 1/1 × 9.56 × 10⁻³ mol = 9.56 × 10⁻³ mol.
Step 4: Calculate the volume occupied by 9.56 × 10⁻³ moles of hydrogen
Assuming standard pressure and temperature, 1 mole of hydrogen occupies 22.4 L.
9.56 × 10⁻³ mol × 22.4 L/1 mol = 0.214 L
We have been given the condition that carbon makes up 35%
of the mass of the substance and the rest is made up of oxygen. With this, it
can be concluded that 65% of the substance is made up of oxygen. If we let x be
the mass of oxygen in the substance, the operation that would best represent
the scenario is,
<span> x = (0.65)(5.5 g)</span>
<span> <em> </em><span><em>x =
3.575 g</em></span></span>
