Answer:
1.55 × 10²⁵ atoms of H
Explanation:
3.21mol C₃H₈ × 8mol H × (6.022×10²³)
Answer:
![\boxed {\boxed {\sf 10.2 \ kJ}}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%2010.2%20%5C%20kJ%7D%7D)
Explanation:
We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.
We will use the following formula to calculate heat energy.
![q=mc \Delta T](https://tex.z-dn.net/?f=q%3Dmc%20%5CDelta%20T)
The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.
- ΔT = final temperature - inital temperature
The aluminum block was heated from 23.0 °C to 73.5 °C.
- ΔT= 73.5 °C - 23.0 °C = 50.5 °C
Now we know all three variables and can substitute them into the formula.
- m= 225 g
- c= 0.897 J/g° C
- ΔT= 50.5 °C
![q= (225 \ g )(0.897 \ J/g \textdegree C)(50.5 \textdegree C)](https://tex.z-dn.net/?f=q%3D%20%28225%20%5C%20g%20%29%280.897%20%5C%20J%2Fg%20%5Ctextdegree%20C%29%2850.5%20%5Ctextdegree%20C%29)
Multiply the first two numbers. The units of grams cancel.
![q= (225 \ g * 0.897 \ J/g \textdegree C)(50.5 \textdegree C)](https://tex.z-dn.net/?f=q%3D%20%28225%20%5C%20g%20%20%2A%200.897%20%5C%20J%2Fg%20%5Ctextdegree%20C%29%2850.5%20%5Ctextdegree%20C%29)
![q= (225 * 0.897 \ J / \textdegree C)(50.5 \textdegree C)](https://tex.z-dn.net/?f=q%3D%20%28225%20%20%20%2A%200.897%20%5C%20J%20%2F%20%5Ctextdegree%20C%29%2850.5%20%5Ctextdegree%20C%29)
![q= (201.825\ J / \textdegree C)(50.5 \textdegree C)](https://tex.z-dn.net/?f=q%3D%20%28201.825%5C%20J%20%2F%20%5Ctextdegree%20C%29%2850.5%20%5Ctextdegree%20C%29)
Multiply again. This time, the units of degrees Celsius cancel.
![q= 201.825 \ J * 50.5](https://tex.z-dn.net/?f=q%3D%20201.825%20%5C%20J%20%2A%2050.5)
![q= 10192.1625 \ J](https://tex.z-dn.net/?f=q%3D%2010192.1625%20%5C%20J)
The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.
![\frac { 1 \ kJ}{ 1000 \ J}](https://tex.z-dn.net/?f=%5Cfrac%20%7B%201%20%20%5C%20kJ%7D%7B%201000%20%5C%20J%7D)
Multiply by the answer we found in Joules.
![10192.1625 \ J * \frac{ 1 \ kJ}{ 1000 \ J}](https://tex.z-dn.net/?f=10192.1625%20%5C%20J%20%2A%20%5Cfrac%7B%201%20%5C%20kJ%7D%7B%201000%20%5C%20J%7D)
![10192.1625 * \frac{ 1 \ kJ}{ 1000 }](https://tex.z-dn.net/?f=10192.1625%20%20%2A%20%5Cfrac%7B%201%20%5C%20kJ%7D%7B%201000%20%7D)
![\frac {10192. 1625}{1000} \ kJ](https://tex.z-dn.net/?f=%5Cfrac%20%7B10192.%201625%7D%7B1000%7D%20%5C%20kJ)
![10.1921625 \ kJ](https://tex.z-dn.net/?f=10.1921625%20%5C%20kJ)
The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.
![10.2 \ kJ](https://tex.z-dn.net/?f=10.2%20%5C%20kJ)
Approximately <u>10.2 kilojoules</u> of energy would be required.
The epidermis, the top layer
The dermis, middle layer
The hypodermis, bottom layer
There you go!
If we don’t protect the ozone layer then it will start to seriously damage earth and we will all eventually die out.
Answer:
Difference between concentrated acid and weak acid :---
- According to Arrhenius's theory the substances which easily get dissociated into H+ ions when dissolved in water are acids.
- And the substance which readily gives H+ ions on dissociation (when dissolved in water) are Strong Acid. Examples are HCl , H2SO4 etc.
While,
- Concentration of acid is just the value of pH. pH is the measurement of concentration of acid or base. The lower the pH, higher the concentration.
- So strong acid is strong because it gives H+ ions readily in water and Concentration is the value of pH.