Answer: -112200J
Explanation:
The amount of heat (Q) released from an heated substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since,
Q = ?
Mass of water vapour = 30.0g
C = 187 J/ G°C
Φ = (Final temperature - Initial temperature)
= 100°C - 120°C = -20°C
Then apply the formula, Q = MCΦ
Q = 30.0g x 187 J/ G°C x -20°C
Q = -112200J (The negative sign does indicates that heat was released to the surroundings)
Thus, -112200 joules of heat is released when cooling the superheated vapour.
Answer:
Discovery of electron while studying the properties of cathode ray by Thomson suggested that Dalton atomic model should be revised.
Explanation:
Electron was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
He constructed the glass tube and create vacuum in it. He applied electric current between electrodes. He noticed that a ray of particles coming from cathode to wards positively charged anode. This ray was cathode ray.
Properties of cathode ray:
The ray is travel in straight line.
The cathode ray is independent of composition of cathode.
When electric field is applied cathode ray is deflected towards the positively charged plate.
Hence it was consist of negatively charged particles.
Symbol= e-
Mass= 9.10938356×10-31 Kg
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Answer:
Its B
Explanation:
Products <=> reactants; products can go back to reactant and reactants can form products, depending on the equilibrium position.
The equilibrium position, if it is on the left, and much of the product is formed. If the equilibrium position is not the right, then its the vice versa The equilibrium position is determined by ;
- <em><u>Temperature</u></em>
If the reaction is endothermic, it will be favoured by increase in temperature and equilibrium position will shift to the right ( reactants )
If the reaction is exothermic, its the vice versa
<em><u>N</u></em><em><u>O</u></em><em><u>T</u></em><em><u>E</u></em><em><u>:</u></em><em><u> </u></em>Only temperature affects the equilibrium position
Answer:
heat energy are absorbed by water molecules and it is used to change the molecules from liquid to gas? if thats what your asking.
Explanation:
The correct answer is + 32.5 J because heat is absorbed here by copper not evolved also after calculation we will find the H value is positive, lets calculate it:
H = m C Δt where:
m = 10 g
C = 0.13 J/g.°C
Δ t = final temperature - initial temperature = 50 - 25 = + 25 °C
so H = 10 x 0.13 x (+25) = + 32.5 J
