Answer:
<u>8.08 × </u>
<u> atoms of hydrogen</u>
Explanation:
From the given data, we have two categories of variables (unknowns):
- Amount (moles or mass) of Caffeine
- Amount (moles or mass) of Hydrogen
The longer route would be to solve for these variables first, by determining the number of moles of the Caffeine sample (0.134 moles of C8H10N4O2) from the mass of carbon (12.89 g = 1.07 moles in 6.47 atoms) provided. And then solve for the number of atoms of H. <u><em>[N.B: 1 mole of ANY substance = 6.022 × </em></u><u><em> atoms ]</em></u>
Alternatively and quicker, we can use the mole ratios of the Carbon:Hydrogen atoms in the compound.
8 : 10 ≡ 4 : 5
If 4 moles -- 6.47 atoms
Then 5 moles -- ?? atoms
⇒ No. of atoms of Hydrogen = 
<u>=8.08 × </u><u> atoms of hydrogen</u>
Answer:
Carson models how the continental crust varies in thickness. Marisol records atmospheric and oceanic temperatures at several beaches. Eliza analyzes seismic wave activity from an earthquake using a computer model.
Answer:
The final pressure of the gas mixture after the addition of the Ar gas is P₂= 2.25 atm
Explanation:
Using the ideal gas law
PV=nRT
if the Volume V = constant (rigid container) and assuming that the Ar added is at the same temperature as the gases that were in the container before the addition, the only way to increase P is by the number of moles n . Therefore
Inicial state ) P₁V=n₁RT
Final state ) P₂V=n₂RT
dividing both equations
P₂/P₁ = n₂/n₁ → P₂= P₁ * n₂/n₁
now we have to determine P₁ and n₂ /n₁.
For P₁ , we use the Dalton`s law , where p ar1 is the partial pressure of the argon initially and x ar1 is the initial molar fraction of argon (=0.5 since is equimolar mixture of 2 components)
p ar₁ = P₁ * x ar₁ → P₁ = p ar₁ / x ar₁ = 0.75 atm / 0.5 = 1.5 atm
n₁ = n ar₁ + n N₁ = n ar₁ + n ar₁ = 2 n ar₁
n₂ = n ar₂ + n N₂ = 2 n ar₁ + n ar₁ = 3 n ar₁
n₂ /n₁ = 3/2
therefore
P₂= P₁ * n₂/n₁ = 1.5 atm * 3/2 = 2.25 atm
P₂= 2.25 atm
Boyle's law of ideal gas: This law states that the volume of a gas is inversely proportional to its pressure at a constant temperature. Acc to this law we can write the relation of pressure and volume as:
That means:
From that equation we can calculate Volume of gas at a certain pressure:
P₁=Initial pressure
V₁=Initial volume
P₂=Final pressure
V₂= Final volume
Here P₁, initial pressure is given as 85.0 kPa
V₁, initial volume is given as 525 mL
P₂, final pressure is 65.0 kPa
so,
V_{2}=85\times 525\div 65
=686 mL
Volume of gas will be 686 mL.
Answer:
Total volume after adding crystal = 26.7 mL
Explanation:
Given data:
Density of crystal = 2.65 g/mL
Mass of sample = 4.46 g
Volume of water = 25.0 mL
Volume after adding crystal = ?
Solution:
First of all we will calculate the volume of crystal.
d = m/v
2.65 g/mL = 4.46 g/ v
v = 4.46 g/2.65 g/mL
v = 1.7 mL
Total volume after adding crystal = Volume of water + Volume of metal
Total volume after adding crystal = 25.0 mL + 1.7 mL
Total volume after adding crystal = 26.7 mL
