The molar mass of NO₂ is 46.0 g/mol
The molar mass of Pb (NO₃)₂ is 331.2 g/mol
First there is a need to find the number of moles of NO₂ via the stoichiometry of reaction:
2Pb(NO₃)₂ → 2PbO (s) + 4NO₂ (g) + 02 (g)
2 × 331.2 g = 4 × 46.0 g
16.87 g = x (mass of NO₂)
mass of NO₂ = 16.87 × 4 × 46 / 2 × 331.2
mass of NO₂ = 3104.08 / 662.4
mass of NO₂ = 4.686 g of NO₂
Now the number of moles are:
1 mole NO₂ = 46.0 g
x moles of NO₂ = 4.686 g
4.686 × 1 / 46.0 = 0.101 moles of NO₂
1 mole = 22.4 L (at STP)
0.101 moles of NO₂ = 0.101 × 22.4 / 1
= 2.26 L
Answer:
Mass of H₂O is 3.0g
Explanation:
The reaction equation is given as:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Parameters that are known:
Mass of CO₂ used = 7.3g
Unknown: mass of water consumed = ?
Solution
To solve this kind of problem, we simply apply some mole concept relationships.
- First, we work from the known to the unknown. From the problem, we have 7.3g of CO₂ that was used. We can find the number of moles from this value using the expression below:
Number of moles of CO₂ = 
- From this number of moles of CO₂, we can use the balanced equation to relate the number of moles of CO₂ to that of H₂O:
6 moles of CO₂ reacted with 6 moles of H₂O(1:1)
- We can then use the mole relationship with mass to find the unknown.
Workings
>>>> Number of moles of CO₂ =?
Molar mass of CO₂ :
Atomic mass of C = 12g
Atomic mass of O = 16g
Molar mass of CO₂ = 12 + (2 x16) = 44gmol⁻¹
Number of moles of CO₂ =
= 0.166moles
>>>>>> if 6 moles of CO₂ reacted with 6 moles of H₂O, then 0.166moles of CO₂ would produce 0.166moles of H₂O
>>>>>> Mass of water consumed = number of mole of H₂O x molar mass
Mass of H₂0 = 0.166 x ?
Molar mass of H₂O:
Atomic mass of H = 1g
Atomic mass of O = 16
Molar mass of H₂O = (2x1) + 16 = 18gmol⁻¹
Mass of H₂O = 0.166 x 18 = 3.0g
The balanced chemical reaction is expressed as:
<span>C3H8 + 5 O2 -> 3 CO2 + 4 H2O
We are given the amount of water produced. We use this amount for the calculations. We do as follows:
16.3 mol H2O ( 1 mol C3H8 / 4 mol H2O ) = 4.075 mol C3H8 needed
Hope this answers the question. Have a nice day.</span>
Rock is a combination of two or more minerals, and it does not possess any specific chemical composition. It is present naturally in the environment. Some examples of rocks are limestone, granite, etc.,Limestone may contain minerals like calcite and aragonite. Each mineral has a specific chemical composition with a well defined crystalline structure.
Therefore, the correct option would be a. rock as rock is the naturally occurring solid mass made up of different types of minerals.