If two objects have different temperatures which direction will heat move for how long

A system receives 575 ) of heat and delivers 425 ) of work. Calculate the change in the internal energy. AE, of the system.

vfiekz [6]

Answer:

ΔE = 150 J

Explanation:

From first law of thermodynamics, we know that;

ΔE = q + w

Where;

ΔE is change in internal energy

q is total amount of heat energy going in or coming out

w is total amount of work expended or received

From the question, the system receives 575 J of heat. Thus, q = +575 J

Also, we are told that the system delivered 425 J of work. Thus, w = -425 J since work was expended.

Thus;

ΔE = 575 + (-425)

ΔE = 575 - 425

ΔE = 150 J

7 0

3 years ago

In an aqueous solution, 42% of a substance dissociates to release hydronium ions. Which of the following statements is true for

const2013 [10]

Answer: The statement it is a weak acid is true for the substance.

Explanation:

An acid that dissociates completely when dissolved in water to give hydrogen $(H^{+})$ or hydronium $(H_{3}O^{+})$ ions is called a strong acid.

For example, HCl is a strong acid.

$HCl + H_{2}O \rightarrow H_{3}O^{+} + Cl^{-}$

An acid that dissociates partially or weakly when dissolved in water to given hydrogen or hydronium ions is called a weak acid.

For example, $CH_{3}COOH$ is a weak acid.

$CH_{3}COOH \rightleftharpoons CH_{3}COO^{-} + H_{3}O^{+}$

A strong base is a base which when dissolved in water then it dissociates completely to give hydroxide ions.

For example, NaOH is a strong acid.

A weak base is a base which when dissolved in water then it dissociates partially or weakly to give hydroxide ions.

For example, $NH_{3}$ is a weak base.

Hence, in an aqueous solution where 42% of a substance dissociates to release hydronium ions shows that the dissociation is less than 50%. This means that substance is dissociating weakly so, it is a weak acid.

Thus, we can conclude that the statement it is a weak acid is true for the substance.

5 0

2 years ago

If all other variables remain unchanged, what happens to the output force when the area of the input piston is doubled?

mars1129 [50]

Answer:

1250N

Explanation:

This question is based on pascal's Law.

So By Pascal's Law

=

therefore =force on input piston =25N

= Force or weight on output person.

therefore after putting the values we get,

= (25x 1500)/30

=1250N

3 0

3 years ago

A block of iron has a mass of 826 g. What is the volume of the block of iron whose density at 25°C is 7.9 ?

kolezko [41]

Answer:

104.56cm³

Explanation:

Mass=826g

Density =7.9g/cm³

Volume =Mass /Density

Volume =826/7.9

Volume =104.56cm³

5 0

1 year ago

Combustion of coal releases sulfur dioxide into the atmosphere. The following process converts this gas into sulfuric acid, a co

Usimov [2.4K]

Answer:

$m=7.07gH_{2}SO_{4}$

Explanation:

1. Take in account the sulfuric acid at STP:

$1840\frac{g}{L}$

2. Density is expressed as the ratio between the mass and the volume of a substance so:

$d=\frac{m}{V}$

Solving for m:

$m=\frac{V}{d}$

3. Replace values:

$m=\frac{1.30*10^{4}L}{1840\frac{g}{L}}$

$m=7.07gH_{2}SO_{4}$

4 0

3 years ago