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Sav [38]
3 years ago
12

An unknown substance undergoes a chemical change that gives off heat. What can you tell me about this substance?

Chemistry
2 answers:
marin [14]3 years ago
7 0
On a molecular level there is a lot of movement which in turn is the reason why heat is generated.
madam [21]3 years ago
3 0

Explanation:

A chemical reaction in which heat is absorbed by the reactant molecules is known as an endothermic reaction.

For example, A + B + Heat \rightarrow AB

On the other hand, a chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.

For example, A + B \rightarrow AB + Heat

Thus, we can conclude that when an unknown substance undergoes a chemical change that gives off heat then it means earlier the substance has more heat energy but after the chemical change there occurs a decrease in its heat energy because some of the heat has been released by it.

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there is a total of seventeen constitutional isomers for the molecular formula c5h13n. draw the skeletal formula of all three co
MAXImum [283]
Amines are derivatives of Ammonia (NH₃) in which atleast one hydrogen atom is replaced by an alkyl group. Amines are further classifies as;

Primary Amines:
                          In primary amines the nitrogen atom is attached to two hydrogen atoms and one alkyl group.

Secondary Amines:
                             In secondary amines the nitrogen atom is attached to two alkyl groups and one hydrogen atom.

Tertiary Amines:
                         In tertiary amines the nitrogen atom is attached to three alkyl groups, hence it has no hydrogen atom.

Below are three isomers of tertiary amines with molecular formula C₅H₁₃N.

5 0
3 years ago
• We obtained the above 10.00-mL solution by diluting a stock solution using a 1.00-mL aliquot and placing it into a 25.00-mL vo
garik1379 [7]

Answer:

a) The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.

b) 0.0035 mole

c)  0.166 M

Explanation:

Phosphoric acid is tripotic because it has 3 acidic hydrogen atom surrounding it.

The equation of the reaction is expressed as:

H_3PO_4 \ + \ 3NaOH -----> Na_3 PO_4 \ + \ 3H_2O

1 mole         3 mole

The relationship at equivalence is that 1 mole of phosphoric acid will need three moles of sodium hydroxide.

b)  if 10.00 mL of a phosphoric acid solution required the addition of 17.50 mL of a 0.200 M NaOH(aq) to reach the endpoint; Then the molarity of the solution is calculated as follows

H_3PO_4 \ + \ 3NaOH -----> Na_3 PO_4 \ + \ 3H_2O

10 ml            17.50 ml

(x) M              0.200 M

Molarity = \frac{0.2*17.5}{1000}

= 0.0035 mole

c) What was the molar concentration of phosphoric acid in the original stock solution?

By stoichiometry, converting moles of NaOH to H₃PO₄; we have

= 0.0035 \ mole \ of NaOH* \frac{1 mole of H_3PO_4}{3 \ mole \ of \ NaOH}

= 0.00166 mole of H₃PO₄

Using the molarity equation to determine the molar concentration of phosphoric acid in the original stock solution; we have:

Molar Concentration =  \frac{mole \ \ of \ soulte }{ Volume \ of \ solution }

Molar Concentration = \frac{0.00166 \ mole \ of \  H_3PO_4 }{10}*1000

Molar Concentration = 0.166 M

∴  the molar concentration of phosphoric acid in the original stock solution = 0.166 M

6 0
3 years ago
You are a researcher for a golf club manufacturer. You are given two identical looking cubes of a metal alloy. You are informed
Rashid [163]

Answer:

C.Melt both cubes and look for a broader range of melting temperatures. The one that melts over a broader range of temperatures is the amorphous solid.

Explanation:

Amorphous solids is one that do not have a fixed melting points but melt over a wide range of temperature due to the irregular shape hence its name. Contrariwise crystalline solids, have a fixed and sharp melting point.

This comes in handy to solve the riddle. We can characterise the pair with the melting point property.

7 0
3 years ago
What is a toxic chemical?
My name is Ann [436]

Answer:any substance which may be harmful to the environment or hazardous to your health if inhaled, ingested or absorbed through the skin.

Explanation:

8 0
3 years ago
Pls help me on this question????
astraxan [27]

Explanation:

The first one is series circuit as it is joined one after another while the second one is parallel circuit joined in a parallel way. Ok the line just like this --------- is the wire , the sign like this | | is the battery and the circles with cross are the bulbs

Hope this helps :) Have a great day

7 0
3 years ago
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