Answer:
75.15 mol.
Explanation:
- Firstly, we need to write the balanced equation of the reaction:
<em>Fe₂O₃ + 3CO → 2Fe + 3CO₂.</em>
It is clear that 1.0 mole of Fe₂O₃ reacts with 3.0 moles of CO to produce 2.0 moles of Fe and 3.0 moles of CO₂.
∴ Fe₂O₃ reacts with CO with (1: 3) molar ratio.
- we need to calculate the no. of moles of (4000 g) of Fe₂O₃:
<em>no. of moles of Fe₂O₃ = mass/molar mass</em> = (4000 g)/(159.69 g/mol) = <em>25.05 mol.</em>
<u>Using cross multiplication:</u>
1.0 mole of Fe₂O₃ needs → 3.0 moles of CO,
∴ 25.05 mole of Fe₂O₃ needs → ??? moles of CO.
<em>∴ The no. of moles of CO needed</em> = (3.0 mol)(25.05 mol)/(1.0 mol) =<em> 75.15 mol.</em>
The correct answer is actually
B) energy that flows from warmer objects to cooler objects.
because temperature is a measure of the average amount of energy possessed by an object due to the random motions of its particles. Heat is the energy that flows from warmer objects to cooler objects. Heat cannot flow in the opposite direction.
Answer:
2-4 minutes
Explanation:
Fastest changing temperature means larger change in temperature when subtracting final temperature from initial temperature in a given time period (given time period is 2 minutes for all the options)
For 0-2 minutes, our final temperature was 40 (at 2 min) and initial temperature was 20 (at 0 min), thus temperature change was only 20 C.
For 2-4, our final temperature was 80 (at 4 min) and initial temperature was 40 (at 2 min) thus temperature change was 40 C.
For 4-6, our final temperature was 100 (at 6 min) and initial temperature was 80 (at 4 min) thus temperature change was 20 C.
We are not given temperature at 8 min so option D is invalid.
As we can clearly see that in a given 2 minute period, option B has the fastest change because it changed 40C when compared to other options that changed only 20C from starting temperature.
Hope that makes sense.
Answer : The given statement is, false.
Explanation :
Ionic product of water : It is defined as the product of the concentration of hydrogen ion and the concentration of hydroxide ion.
The mathematical expression will be,
![[H^+][OH^-]=10^{-14}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%5BOH%5E-%5D%3D10%5E%7B-14%7D)
When the concentration of hydrogen ion and hydroxide ion are equal then the solution is neutral and the value will be, 
. And the pH of the solution is, 7.
When the concentration of hydrogen ion is greater than then the solution is acidic in nature. And the pH of the solution is, less than 7.
When the concentration of hydrogen ion is less than then the solution is basic in nature. And the pH of the solution is, greater than 7.
Hence, the given statement is false.
