Answer:
4.13×10²⁷ molecules of N₂ are in the room
Explanation:
ideal gases Law → P . V = n . R . T
Pressure . volume = moles . Ideal Gases Constant . T° K
T°K = T°C + 273 → 20°C + 273 = 293K
Let's determine the volume of the room:
18 ft . 18 ft . 18ft = 5832 ft³
We convert the ft³ to L → 5832 ft³ . 28.3L / 1 ft³ = 165045.6 L
1 atm . 165045.6 L = n . 0.082 L.atm/mol.K . 293K
(1 atm . 165045.6 L) / 0.082 L.atm/mol.K . 293K = n
6869.4 moles of N₂ are in the room
If we want to find out the number of molecules we multiply the moles by NA
6869.4 mol . 6.02×10²³ = 4.13×10²⁷ molecules
Answer:
D. It is a chemical reaction because the total mass remains the same when new substances are formed.
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen. The number of atoms are same on both side however arrangement of atoms is different.
While in case of nuclear reaction small change in mass take place.
The mass percent of hydrogen in CH₄O is 12.5%.
<h3>What is the mass percent?</h3>
Mass percent is the mass of the element divided by the mass of the compound or solute.
- Step 1: Calculate the mass of the compound.
mCH₄O = 1 mC + 4 mH + 1 mO = 1 (12.01 amu) + 4 (1.00 amu) + 1 (16.00 amu) = 32.01 amu
- Step 2: Calculate the mass of hydrogen in the compound.
mH in mCH₄O = 4 mH = 4 (1.00 amu) = 4.00 amu
- Step 3: Calculate the mass percent of hydrogen in the compound.
%H = (mH in mCH₄O / mCH₄O) × 100%
%H = 4.00 amu / 32.01 amu × 100% = 12.5%
The mass percent of hydrogen in CH₄O is 12.5%.
Learn more about mass percent here:brainly.com/question/4336659
Considering the Charles's law, the sample of carbon dioxide gas will occupy 308.72 mL.
<h3>Charles's law</h3>
Charles's law establishes the relationship between the temperature and the volume of a gas when the pressure is constant. This law says that the volume is directly proportional to the temperature of the gas: for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases.
Mathematically, Charles's law states that the ratio between volume and temperature will always have the same value:
Considering an initial state 1 and a final state 2, it is fulfilled:
<h3>Final volume in this case</h3>
In this case, you know:
- V1= 250 mL
- T1= 25 C= 298 K (being 0 C=273 K)
- V2= ?
- T2= 95 C= 368 K
Replacing in Charles's law:
Solving:
<u><em>V2= 308.72 mL</em></u>
Finally, the sample of carbon dioxide gas will occupy 308.72 mL.
Learn more about Charles's law:
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Answer:Mechanical weathering
weathering breaks down rocks by forming new minerals that are stable at the Earth's surface.
