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3 years ago

What is an example of conduction, raditaon convection

Chemistry

1 answer:

Tom [10]3 years ago

3 0

Answer:

convection could be a pot on a stove, radiation could be the sun and heat waves, and conduction could be a cup with coffee.

Explanation:

Conduction occurs when two objects are in direct contact with each other.

Convection is the transfer of heat through liquids and gases. Convection occurs above a hot surface because hot air expands and rises and is replaced by cooler, denser air.

Radiate energy is given off by a hot object and directly absorbed by another cooler object. This cause the cooler object to get warmer. Radiation can occur even if no air is present.

You might be interested in

What is the oxidation number of phosphorus (P) in phosphoric acid (H3PO4)?

Sedaia [141]

Hey there!:

H is always +1 so the H's have a +3 charge.

O is always -2 so the O's have a -8 charge .

Now, suppose oxidation state for P = X , then :

+3 + X + (-8) = 0 (because of neutral molecule)

x = 8 - 3

x = + 5

So, X = +5 oxidation state.

Answer C

Hope that helps!

4 0

2 years ago

Three kilograms of steam is contained in a horizontal, frictionless piston and the cylinder is heated at a constant pressure of

lakkis [162]

Answer:

Final temperature: 659.8ºC

Expansion work: 3*75=225 kJ

Internal energy change: 275 kJ

Explanation:

First, considering both initial and final states, write the energy balance:

$U_{2}-U_{1}=Q-W$

Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:

$dw=Pdv$

The pressure is constant, so: $w=P(v_{2}-v_{1} )=0.5*100*1.5=75\frac{kJ}{kg}$ (There is a multiplication by 100 due to the conversion of bar to kPa)

So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):

$U_{2}-U_{1}=500-(3*75)=275kJ$

On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:

$P_{1}V_{1}=nRT_{1}$

$P_{2}V_{2}=nRT_{2}\\V_{2}=2.5V_{1}\\P_{2}=P_{1}\\2.5P_{1}V_{1}=nRT_{2}$

Subtracting the first from the second:

$1.5P_{1}V_{1}=nR(T_{2}-T_{1})$

Isolating $T_{2}$ :

$T_{2}=T_{1}+\frac{1.5P_{1}V_{1}}{nR}$

Assuming that it is water steam, n=0.1666 kmol

$V_{1}=\frac{nRT_{1}}{P_{1}}=\frac{8.314*0.1666*373.15}{500} =1.034m^{3}$

$T_{2}=100+\frac{1.5*500*1.034}{0.1666*8.314}=659.76$ ºC

7 0

3 years ago

For the reaction between aqueous solutions of acetic acid (CH3COOH) and barium hydroxide, Ba(OH)2, write

borishaifa [10]

Answer:

See explanation.

Explanation:

Hello!

In this case, since we are asked to note down the complete molecular equation, complete ionic equation and the net ionic equation for the reaction between acetic acid (weak acid) and barium hydroxide (strong base), we proceed as shown below:

- Complete molecular equation:

$2CH_3COOH(aq)+Ba(OH)_2(aq)\rightarrow Ba(CH_3COO)_2(aq)+2H_2O(l)$

- Complete ionic equation: in this case, since acetic acid is a weak one, it is not ionized, so we do this:

$2CH_3COOH(aq)+Ba^{2+}(aq)+2OH^-(aq)\rightarrow Ba^{2+}(aq)+2CH_3COO^-(aq)+2H_2O(l)$

- Net ionic equation: in this case, we cancel out the barium ions as they are the spectators one because they are present at both reactants and products:

$2CH_3COOH(aq)+2OH^-(aq)\rightarrow 2CH_3COO^-(aq)+2H_2O(l)\\\\CH_3COOH(aq)+OH^-(aq)\rightarrow CH_3COO^-(aq)+H_2O(l)$