Answer:
Time taken 172.8 years
Explanation:
Given data:
Total amount of strontium-90 = 1000.0 g
Amount left = 15.625 g
Half life of strontium = 28.8 years
Time taken = ?
Solution:
Number of half lives:
At time zero = 1000.0 g
At first half life = 1000.0g/2 = 500 g
At second half life = 500 g/2 = 250 g
At third half life = 250 g/ 2 = 125 g
At 4th half life = 125 g/ 2= 62.5 g
At 5th half life = 62.5 g/2 = 31.25 g
At 6th half life = 31.25 g / 2 = 15.625 g
Time taken:
Time taken = number of half lives × half life
Time taken = 6×28.8 years
Time taken = 172.8 years
The atomic weight of H is 1, O is 16.
There are two of each in a hydrogen peroxide molecule.
(1*2)+(16*2)=2+32
2+32=34
The weight of the whole molecule is 34, and hydrogen makes up 2 of that.
(2/34)*100=0.0588235294*100
0.0588235294*100=5.88235294
The percentage mass of hydrogen in a hydrogen peroxide molecule is 5.88%
Answer:
The answer is 0.36 kg/s NO
Explanation:
the chemical reaction of NH3 to NO is as follows:
4NH3(g) + 5O2(g) ⟶4 NO(g) +6 H2O(l)
We have the following data:
O2 Volume rate = 645 L/s
P = 0.88 atm
T = 195°C + 273 = 468 K
NO molecular weight = 30.01 g/mol
we calculate the moles found in 645 L of O2:
P*V = n*R*T
n = P*V/R*T
n= (0.88 atm * 645L/s)/((0.08205 L*atm/K*mol) * 468 K) = 14.78 moles of O2
With the reaction we can calculate the number of moles of NO and with its molecular weight we will have the rate of NO:
14.78 moles/s O2 * 4 molesNO/5 molesO2 * 30.01 g NO/1 molNO x 1 kgNO/1000 gNO = 0.36 kg/s NO
Answer:
3.15 × 10⁻⁶ mol H₂/L.s
1.05 × 10⁻⁶ mol N₂/L.s
Explanation:
Step 1: Write the balanced equation
2 NH₃ ⇒ 3 H₂ + N₂
Step 2: Calculate the rate of production of H₂
The molar ratio of NH₃ to H₂ is 2:3. Given the rate of decomposition of NH₃ is 2.10 × 10⁻⁶ mol/L.s, the rate of production of H₂ is:
2.10 × 10⁻⁶ mol NH₃/L.s × 3 mol H₂/2 mol NH₃ = 3.15 × 10⁻⁶ mol H₂/L.s
Step 3: Calculate the rate of production of N₂
The molar ratio of NH₃ to N₂ is 2:1. Given the rate of decomposition of NH₃ is 2.10 × 10⁻⁶ mol/L.s, the rate of production of N₂ is:
2.10 × 10⁻⁶ mol NH₃/L.s × 1 mol N₂/2 mol NH₃ = 1.05 × 10⁻⁶ mol N₂/L.s
