All categories

3 years ago

Which of these describes an endothermic process?

Chemistry

2 answers:

vfiekz [6]3 years ago

4 0

Answer:

3rd one

Explanation:

"when barium hydroxide is mixed with ammonium chloride, ice crystals form on the outside of the container" is the correct answer to describe the endothermic process.

Phoenix [80]3 years ago

3 0

The third one down: "When barium hydroxide is mixed with ammonium chloride, ice crystals form on the outside of the container."

This is because an endothermic reaction [process] takes in more energy than it releases. Therefore because a decrease in energy leads to a decrease in temperature, the ice crystals forming show that it must be a endothermic reaction [process].

Hope this helps! :)
AJ

You might be interested in

A concentrated salt solution has a mass of 5.222 g for a 5.000 mL sample.

ad-work [718]

The specific gravity or relative density of a substance is the ratio of its density to the density of a reference material. The relative density of the concentrated salt solution is 1.044.

Mathematically;

Density of the concentrated salt = mass of salt/volume of salt = 5.222 g/5.000 mL = 1.044 g/mL

In the case of specific gravity, the reference material is always water and water has a density of 1 g/mL.

Hence, specific gravity of the concentrated salt solution =

Density of concentrated salt solution/density of equal volume of water

= 1.044 g/mL/1 g/mL

= 1.044

Note that specific gravity is dimensionless.

Learn more: brainly.com/question/9638888

6 0

3 years ago

Which is a single ringed nitrogeo base?<br><br> A)adenine<br> B)guanine<br> C)thymine<br> D)ribose

pogonyaev

A single ringed nitrogeo base is thymine (C)

3 0

3 years ago

What are sister chromatids?

kogti [31]

The female part of the chromosomes, usually colored pink in diagrams

3 0

3 years ago

Read 2 more answers

The equilibrium constant has been estimated to be 0.12 at 25 °C. If you had originally placed 0.069 mol of cyclohexane in a 2.8

scZoUnD [109]

Answer: Concentrations of cyclohexane and methylcyclopentane at equilibrium are 0.0223 M and 0.0027 M respectively

Explanation:

Moles of cyclohexane = 0.069 mole

Volume of solution = 2.8 L

Initial concentration of cyclohexane = $\frac{moles}{Volume}=\frac{0.069}{2.8}=0.025M$

The given balanced equilibrium reaction is,

cyclohexane ⇔ methylcyclopentane

Initial conc. 0.025 M 0

At eqm. conc. (0.025-x)M (x) M

The expression for equilibrium constant for this reaction will be,

K= methylcyclopentane / cyclohexane

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

$0.12=\frac{(x)}{(0.025-x)}$

By solving the term 'x', we get :

x = 0.0027

Concentration of cyclohexane at equilibrium = (0.025-x ) M = (0.025-0.0027) M = 0.0223 M

Concentration of methylcyclopentane at equilibrium = (x ) M = (0.0027) M

4 0

3 years ago

Extend your thinking: The slow decay of radioactive materials can be used to find the age of rocks, fossils, and archaeological

lisov135 [29]

The age in years of the Egyptian papyrus, the Aboriginal charcoal, the Mayan headdress, and the Neanderthal skull are 4000 years, 13106.5years , 2040 years, and 30353 years respectively.

<h3>What is the half-life of a radioactive material?</h3>

The half-life of a radioactive material is the time taken for half the atoms present in the material to decay or disintegrate.

The half-life, $t_\frac{1}{2}$ , the age, t, and amount remaining, $A_{r}$ , of a radioactive material are related by the formula below:

$t = \frac{t_\frac{1}{2}*A_{r}}{-ln2}$

Half-life of carbon-14 = 6000 years

For the Egyptian papyrus with 63% of its original carbon-14 atoms: $t = \frac{6000*0.63}{-0.63} = 4000\:years$

For the Aboriginal charcoal with 22% of its original carbon-14 atoms:

$t = \frac{6000*0.22}{-0.63} = 13106.5\:years$

For the Mayan headdress with 79% of its original carbon-14 atoms:

$t = \frac{6000*0.79}{-0.63} = 2040\:years$

Neanderthal skull with 3% of its original carbon-14 atoms:

$t = \frac{6000*0.03}{-0.63} = 30353\:years$

Therefore, the age in years of the Egyptian papyrus, the Aboriginal charcoal, the Mayan headdress, and the Neanderthal skull are 4000 years, 13106.5years , 2040 years, and 30353 years respectively.

Learn more about half-life at: brainly.com/question/26689704

#SPJ1

6 0

2 years ago