Which of the following is not a phase change?

Limestone stalactites and stalagmites are formed in caves by the following reaction: Ca2 (aq) 2HCO−3(aq)→CaCO3(s) CO2(g) H2O(l)

Vesna [10]

Answer : The value of $\Delta E$ for this reaction is 36.18 kJ

Explanation :

First law of thermodynamic : It states that the energy can not be created or destroyed, it can only change or transfer from one state to another state.

As per first law of thermodynamic,

$\Delta E=q+w$

where,

$\Delta E$ = internal energy of the system

q = heat added or rejected by the system

w = work done

As we are given that:

q = 38.65 kJ

w = -2.47 kJ (system work done on surrounding)

Now put all the given values in the above expression, we get:

$\Delta E=38.65kJ+(-2.47kJ)$

$\Delta E=36.18kJ$

Therefore, the value of $\Delta E$ for this reaction is 36.18 kJ

6 0

2 years ago

4. How many grams of ammonium carbonate are needed to decompose in order to produce

Thepotemich [5.8K]

Answer:

14.23g of (NH4)2CO3

Explanation:

We'll begin by writing the balanced equation for the reaction.

(NH4)2CO3 –> (NH4)2O + CO2

Next,, we shall determine the mass of (NH4)2CO3 that decomposed and the mass of CO2 produced from the balanced equation. This is illustrated below:

Molar mass of (NH4)2CO3 = 2[14+(4x1)] + 12 + (16x3)

= 2[14 +4] + 12 + 48

= 2[18] + 60 = 96g/mol

Mass of (NH4)2CO3 from the balanced equation = 1 x 96 = 96g

Molar mass of CO2 = 12 + (2x16) = 44g/mol

Mass of CO2 from the balanced equation = 1 x 44 = 44g.

Summary:

From the balanced equation above,

96g of (NH4)2CO3 decomposed to produce 44g of CO2.

Finally, we can determine the mass of (NH4)2CO3 that decomposed to produce 6.52g of CO2 as follow:

From the balanced equation above,

96g of (NH4)2CO3 decomposed to produce 44g of CO2.

Therefore, Xg of (NH4)2CO3 will decompose to produce 6.52g of CO2 i.e

Xg of (NH4)2CO3 = (96 x 6.52)/44

Xg of (NH4)2CO3 = 14.23g

Therefore, 14.23g of (NH4)2CO3 is needed to produce 6.52g of CO2.

4 0

2 years ago

1. Define flash flood.

BigorU [14]

A flash flood is when to much water overflows a certain area. This is common with storms. When it rains; small bridges tend to floor. Garages, basements, and cellars can tend to flood as well from storms.

7 0

2 years ago

Read 2 more answers

What type of subatomic particles are found in the cloud?

Novay_Z [31]

Answer:

Electrons are particles that surround the nucleus of an atom like a cloud. As with protons and neutrons, electrons are essential to an atom's structure.

8 0

2 years ago

In stars, hydrogen nuclei combine with each other to form helium and other heavier elements. what is this process called?

slega [8]

Hello!

The process in which hydrogen nuclei combine with each other to form helium and other heavier elements is called Nuclear Fusion.

Nuclear Fusion happens when the repulsion between the two nuclei is overcome by the Strong Interaction Force, spending and releasing high amounts of energy.

The two nuclei need to be close enough for Nuclear Fusion to happen, and the energy needed to achieve that is given by the extremely hot temperatures that exist within stars (about 15 000 000 Kelvin). That's why this kind of reactions are common in stars.

Have a nice day!

6 0

2 years ago