Answer:
Convection.
Explanation:
Let us define each of the type of thermal transfer first:
- radiation is heat transfer that does not include contact between the objects. It's mediated by infra-red radiation, waves from the invisible radiation spectrum.
- conduction is heat transfer which is mediated through direct contact between objects (holding a hot cup of tea, for example)
- convection is a heat transfer found in gases and liquids. Due to different temperatures in two parts of liquid, there will also be a different density ( hotter parts have lower density). Lower density parts will start moving upwards while higher density parts, due to gravity, will move downward. As they move, they will gain or receive heat, which will cause new temperature differences and the moving will restart.
Answer:
If an item is less dense, it floats on the water.
Explanation:
We know this since the more dense something it usually is heavier than if it was less dense. Which ways it down resulting to it sinking.
Answer:
Mass of SO₂ can be made from 25.0 g of Na₂SO₃ and 22 g of HCl = 12.672 g
Explanation:
SO₂( sulfur dioxide) can be produced in the lab. by the reaction of hydrochloric acid & sulphite salt such as sodium.
the balanced chemical equation is as follows
Na₂SO₃ + 2 HCl → 2 NaCl + SO₂ + H₂O
Moles of Na₂SO₃ = ![\frac{Mass}{Molecular mass} =\frac{25}{126} = 0.198](https://tex.z-dn.net/?f=%5Cfrac%7BMass%7D%7BMolecular%20mass%7D%20%3D%5Cfrac%7B25%7D%7B126%7D%20%3D%200.198)
Moles of HCl = ![\frac{mass}{molecular mass}=\frac{22}{36.5}= 0.6](https://tex.z-dn.net/?f=%5Cfrac%7Bmass%7D%7Bmolecular%20mass%7D%3D%5Cfrac%7B22%7D%7B36.5%7D%3D%200.6)
using mole ratio method to find limiting reagent
For sodium sulfite ![\frac{mole}{stoichiometry} = \frac{0.198}{1}= 0.198](https://tex.z-dn.net/?f=%5Cfrac%7Bmole%7D%7Bstoichiometry%7D%20%20%3D%20%5Cfrac%7B0.198%7D%7B1%7D%3D%200.198)
for HCl ![\frac{mole}{stoichiometry} = \frac{0.6}{2}= 0.3](https://tex.z-dn.net/?f=%5Cfrac%7Bmole%7D%7Bstoichiometry%7D%20%20%3D%20%5Cfrac%7B0.6%7D%7B2%7D%3D%200.3)
since <u>sodium sulfite</u> is <u>limiting reactant</u> for above chemical reaction
1 mole of Na₂SO₃ produce 1 mole of SO₂
0.198 mole of Na₂SO₃ produce 0.198 mole of SO₂
∴ Mass of SO₂ produce = mole x molar mass of SO₂
= 0.198 x 64
= 12.672 g
Answer: Polythene
Polythene is a synthetic polymer classified as plastics.
Explanation:
Polythene is formed artificially from several repeating units of ethene molecules (monomers) in a reaction known as polymerization.
The polyethene can be represented as [CH2-CH2]n, where n is thousands to ten thousands unit of ethene.
It is used to make
- plastic bags,
- cable insulators
- plastic crates etc
Thus, polythene is a synthetic polymer of ethene, and classified as plastics.
Answer : The correct option is, (C) 1.1
Solution : Given,
Initial moles of
= 1.0 mole
Initial volume of solution = 1.0 L
First we have to calculate the concentration
.
![\text{Concentration of }N_2O_4=\frac{\text{Moles of }N_2O_4}{\text{Volume of solution}}](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20%7DN_2O_4%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20%7DN_2O_4%7D%7B%5Ctext%7BVolume%20of%20solution%7D%7D)
![\text{Concentration of }N_2O_4=\frac{1.0moles}{1.0L}=1.0M](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20%7DN_2O_4%3D%5Cfrac%7B1.0moles%7D%7B1.0L%7D%3D1.0M)
The given equilibrium reaction is,
![N_2O_4(g)\rightleftharpoons 2NO_2(g)](https://tex.z-dn.net/?f=N_2O_4%28g%29%5Crightleftharpoons%202NO_2%28g%29)
Initially c 0
At equilibrium
![2c\alpha](https://tex.z-dn.net/?f=2c%5Calpha)
The expression of
will be,
![K_c=\frac{[NO_2]^2}{[N_2O_4]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BNO_2%5D%5E2%7D%7B%5BN_2O_4%5D%7D)
![K_c=\frac{(2c\alpha)^2}{(c-c\alpha)}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%282c%5Calpha%29%5E2%7D%7B%28c-c%5Calpha%29%7D)
where,
= degree of dissociation = 40 % = 0.4
Now put all the given values in the above expression, we get:
![K_c=\frac{(2c\alpha)^2}{(c-c\alpha)}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%282c%5Calpha%29%5E2%7D%7B%28c-c%5Calpha%29%7D)
![K_c=\frac{(2\times 1\times 0.4)^2}{(1-1\times 0.4)}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%282%5Ctimes%201%5Ctimes%200.4%29%5E2%7D%7B%281-1%5Ctimes%200.4%29%7D)
![K_c=1.066\aprrox 1.1](https://tex.z-dn.net/?f=K_c%3D1.066%5Caprrox%201.1)
Therefore, the value of equilibrium constant for this reaction is, 1.1