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3 years ago

Which statement is true of a chemical change? (Plato)

Chemistry

2 answers:

MrRa [10]3 years ago

6 0

Answer: i think A

Explanation: if i got it right could you mark me as brainliest

OleMash [197]3 years ago

5 0

Answer:

Explanation:

The answer A is the best answer because it contains the most general characteristic of a chemical change.

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Argon, which comprises almost 1% of the atmosphere, is approximately 27 times more abundant than CO 2, but does not contribute t

kotegsom [21]

Answer:

The gas argon does not reach a state of vibrational excitation when infrared radiation strikes this gas.

Explanation:

The dry atmosphere is composed almost entirely of nitrogen (in a volumetric mixing ratio of 78.1%) and oxygen (20.9%), plus a series of oligogases such as argon (0.93%), helium and gases of greenhouse effect such as carbon dioxide (0.035%) and ozone. In addition, the atmosphere contains water vapor in very variable amounts (about 1%) and aerosols.

Greenhouse gases or greenhouse gases are the gaseous components of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at certain wavelengths of the infrared radiation spectrum emitted by the Earth's surface, the atmosphere and clouds . In the Earth's atmosphere, the main greenhouse gases (GHG) are water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3 ). There is also in the atmosphere a series of greenhouse gases (GHG) created entirely by humans, such as halocarbons (compounds containing chlorine, bromine or fluorine and carbon, these compounds can act as potent greenhouse gases in the atmosphere and they are also one of the causes of the depletion of the ozone layer in the atmosphere) regulated by the Montreal Protocol. In addition to CO2, N2O and CH4, the Kyoto Protocol sets standards regarding sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs).

The difference between argon and greenhouse gases such as CO2 is that the individual atoms in the argon do not have free bonds and therefore do not vibrate. As a consequence, it does not reach a state of vibrational excitation when infrared radiation strikes this gas.

6 0

3 years ago

The mass of a nucleus is 0.042 amu less than the sum of the masses of 3 protons and 4 neutrons. The binding energy per nucleon i

Leni [432]

The answer is 10 mev. hope this helps

4 0

2 years ago

Read 2 more answers

Write a chemical equation of Dr. Jeff’s demonstration using a battery to light steel wool on fire. The battery is used to allow

Elis [28]

Answer:

2Fe(s) + 3O2(g) --------> 2FeO3(s)

Explanation:

According to the question, a battery was used to light the steel wool by bringing the terminals very close together. When the battery came into contact with the steel wool, current was sent out through the thin wire. This caused the iron to heat up quite well.

Iron reacts with oxygen under these conditions as follows;

2Fe(s) + 3O2(g) --------> 2FeO3(s)

This is the chemical reaction that occurs when the steel wool is set on fire.

6 0

2 years ago

3g of clean mg ribbon and 8g of clean copper metal was burnt separately in equal volume of air and both mass reacted completely

dsp73

Answer:

gshshs

Explanation:

bshsjskskehhshs

5 0

2 years ago

You mix 200. mL of 0.400M HCl with 200. mL of 0.400M NaOH in a coffee cup calorimeter. The temperature of the solution goes from

GuDViN [60]

Answer : The enthalpy of neutralization is, 56.012 kJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=0.400mole/L\times 0.200L=0.08mol$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=0.400mole/L\times 0.200L=0.08mol$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.08 mole of HCl neutralizes by 0.08 mole of NaOH

Thus, the number of neutralized moles = 0.08 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $200mL+200L=400mL$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 400mL=400g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 400 g

$T_{final}$ = final temperature of water = $27.78^oC=273+25.10=300.78K$

$T_{initial}$ = initial temperature of metal = $25.10^oC=273+27.78=298.1K$

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

$q=400g\times 4.18J/g^oC\times (300.78-298.1)K$

$q=4480.96J$

Thus, the heat released during the neutralization = -4480.96 J

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -4480.96 J

n = number of moles used in neutralization = 0.08 mole

$\Delta H=\frac{-4480.96J}{0.08mole}=-56012J/mole=-56.012kJ/mol$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 56.012 kJ/mole

8 0

2 years ago