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3 years ago

All the following are signs of a chemical reaction, except

Chemistry

2 answers:

hodyreva [135]3 years ago

8 0

C. a change of state. It can be a physical or a chemical state of change.

kaheart [24]3 years ago

6 0

C. a change of state.

Signs of a chemical reaction include;
Change of color
formation of gas
change of temperature
Precipitate formation
Energy production.

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The Ostwald process is used commercially to produce nitric acid, which is, in turn, used in many modern chemical processes. In t

Sloan [31]

Answer:

Mass = 42.8g

Explanation:

4 NH 3 ( g ) + 5 O 2 ( g ) ⟶ 4 NO ( g ) + 6 H 2 O ( g )

Observe that every 4 mole of ammonia requires 5 moles of oxygen to obtain 4 moles of Nitrogen oxide and 6 moles of water.

Step 1: Determine the balanced chemical equation for the chemical reaction.

The balanced chemical equation is already given.

Step 2: Convert all given information into moles (through the use of molar mass as a conversion factor).

Ammonia = 63.4g × 1mol / 17.031 g = 3.7226mol

Oxygen = 63.4g × 1mol / 32g = 1.9813mol

Step 3: Calculate the mole ratio from the given information. Compare the calculated ratio to the actual ratio.

If all of the 1.9831 moles of oxygen were to be used up, there would need to be 1.9831 × 4 / 5 or 1.5865 moles of Ammonia. We have 3.72226 moles of ammonia - Far excess. Because there is an excess of Ammonia, the Oxygen amount is used to calculate the amount of the products in the reaction.

Step 4: Use the amount of limiting reactant to calculate the amount of H2O produced.

5 moles of O2 = 6 moles of H2O

1.9831 moles = x

x = (1.9831 * 6 ) / 5

x = 2.37972 moles

Mass of H2O = Molar mass * Molar mass

Mass = 2.7972 * 18

Mass = 42.8g

6 0

3 years ago

The specific heat of copper metal is 0. 385 J/(g °C). How much energy must be added to a 35. 0-gram sample of copper to change t

Rus_ich [418]

The amount of heat required for changing the temperature of copper has been 606 J. Thus, option B is correct.

Specific heat has been defined as the amount of heat required to raise the temperature of 1 gram of substance by 1 degree Celsius.

The heat required to raise the temperature has been expressed as:

$\rm Heat=mass\;\times\;specific\;heat\;\times\;Change\;in\;temperature$

<h3>Computation for the heat energy required</h3>

The given specific heat of copper has been $\rm 0.385\;J/g^\circ C$

The mass of copper has been, $\rm 35\;g$

The initial temperature of copper has been, $\rm 20^\circ C$

The final temperature of copper has been, $\rm 65^\circ C$

The change in temperature has been, $\Delta T$

$\Delta T=\text{Final\;temperature-Initial\;temperature}\\\Delta T =65^\circ \text C-20^\circ \text C\\\Delta T=45^\circ \text C$

Substituting the values for the heat required as:

$\rm Heat=35\;g\;\times\;0.385\;J/g^\circ C\;\times\;45^\circ C\\Heat=606\;J$

The amount of heat required for changing the temperature of copper has been 606 J. Thus, option B is correct.

Learn more about specific heat, here:

brainly.com/question/2094845

7 0

2 years ago

What wave has the longer wavelength

natima [27]

The wavelength is the distance between one crest/trough to another crest/trough. On the image, it's basically the length between each peak of the wave. You can see that the distance between peaks in wave A are much shorter than the distance between the peaks in wave B.

Thus, wave B has the longer wavelength.

8 0

3 years ago

How do you make a guy who is extremely into you, even though he knows you aren't single, to bug off?

kvasek [131]

Be kind yk? tell him have some respect for your relationship and if he can't then cut him off completely

3 0

3 years ago

Read 2 more answers

Ions that have the same electron configuration are called

Katena32 [7]

Such ions are said to be isoelectronic

3 0

3 years ago