Answer:
B
Explanation:
reaction order is simply the sum of orders for each reactant.
<span>Fe(OH)3(S) +3HNO3(aq)----->Fe(NO3)3(aq) + 3H20(aq)
M(Fe(OH)3)=56+48+3=107; M(HNO3)= 48+14+1=63
n(Fe(OH)3)=5.4/107=0.05; n(HNO3)=2.6/63=0.04
n(Fe(OH)3):n(HNO3)=1:3, which means that the HNO3 should be three times (molar) than the Fe(OH)3, but you can see that it is, actually, even less than the Fe(OH)3, meaning that HNO3 is the limiting reagent and the amount of Fe(OH)3 which is going to react with HNO3 is 0.04/3=0.013 i.e. 0.05-0.013=0.037 mol Fe(OH)3 is left after the completion.
Just in case you can convert it into mass, but I suppose this is enough.</span>
Answer:
A
Explanation:
temperature increase because burning causes heat therefore the planet heats up from all the fossil fuels burned aka "global warming"
Answer:
The moles of KClO3 = 0.052 moles
Explanation:
Step 1: Calculate the pressure of oxygen gas
The oxygen has a total pressure (including water vapour) of 760 mmHg
The pressure of Oxygen = (760 - 26) mmHg
= 734 mmHg of water vapor
Step 2: Calculate the no of moles of oxygen
Using Ideal gas equation
P V = n R T
P = pressure of oxygen in N/m2 ( you should convert 734 mmHg to pascal or N/m2) = 97,858.6 N/m2 or pas
V = 2 litres = 0.002 m3
R = gas constant = 8.31
T= 27oC = 300 K
Applying this equation P V = n R T
97,858.6 x 0.002 = n x 8.31 x 300
n = 0.0785 mol of Oxygen
From the balanced equation
2 KClO 3 ---- 2 KCl + 3 O 2
3 moles of oxygen is produced from 2 moles KClO3
so 0.0785 mole of oxygen will be produced from x
x = (0.0785 x 2 ) / 3
x = 0.052 moles of KClO3
<h3>
Answer:</h3>
28.52 seconds
<h3>
Explanation:</h3>
Initial number of atoms of Nitrogen 12,000 atoms
Half-life = 7.13
Number of atoms after decay = 750 atoms
We are required to determine the time taken for the decay.
Note that half life is the time taken for a radioactive isotope to decay to a half of its original amount.
Using the formula;
Remaining amount = Initial amount × (1/2)^n , where n is the number of half lives
In our case;
750 atoms = 12,000 atoms × (1/2)^n
0.0625 = 0.5^n
n = log 0.0625 ÷ log 0.5
n = 4
But, 1 half life =7.13 seconds
Therefore;
Time taken = 7.13 seconds × 4
= 28.52 seconds
Therefore, the time taken for 12,000 atoms of nitrogen to decay to 750 atoms is 28.52 seconds
