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3 years ago

Which of the following statements is true?

1 answer:

5 0

The first statement is False... as
For exothermic reaction :
A+B》 C+D + HEAT..(heat is considered as a product)... as for endo.. heat is a reactant.
So tjey can't be of the same energy...

2nd one...based on the
A+B》 C+D+HEAT...For exo reaction... the product have more Heat energy than potential...so its false
Recall...energy can nither be created nor destroyed but converted from one form to another....

The 4th one however is true for heat...the reactants have nore energy than the products..
A+B+HEAT》C+D

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A compound is a pure substance composed of two or more elements, combined by chemical means, in a definite ratio. Which containe

strojnjashka [21]

Answer:

H20

Explanation:

H20 (WATER) is a compound because its constituent atoms, oxygen and hydrogen are present in a definite ratio (1:2)

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4 years ago

There are three different dichloroethylenes (molecular formula C₂H₂Cl₂), which we can designate X, Y, and Z. Compound X has no d

Alexxandr [17]

Compound X= (E)-1,2-dichloroethene

Compound Y= 1,1-dichloroethene

Compound Z= (Z)-1,2-dichloroethene

Elaboration :

In this case we will have 3 isomers which have the same formula. If we use the formula, the options we have are that the chlorides are attached to the same carbon (compound Y) or different carbons (Compounds X and Y).

Now, the problem gives a clue about compounds X and Y, hydrogenation results in the same compound (see figure) therefore the only difference between the compounds is the orientation of the Cl groups, therefore one of them it must be "E" and the other "Z" (this nomenclature should be used for alkenes, since the cis / trans nomenclature is used for other types of molecules),

so the question is which is the cis isomer and which is the Isomer Z ?

The problem says that compound X has no dipole moment, therefore in compound X the Cl groups must have opposite directions such that the dipole moments of both cancel each other out. In conclusion, compound X is the isomer E, compound Y is the compound in which the Cl groups are on the same carbon and compound z is the isomer Z.

So, yes Y will have a dipole moment

Dipole moment :

A dipole moment is a measurement of the separation of two opposite electrical charges. Dipole moments are a vector quantity. The magnitude is equal to the charge multiplied by the distance between the charges and the direction is from negative charge to positive charge: μ = q · r.

Learn more about dipole moments :

brainly.com/question/1594280

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1 year ago

Kemmi Major does some experimental work on the combustion of sucrose: C12H22O11(s) 12 O2(g) → 12 CO2(g) 11 H2O(g) She burns a 0.

Pavlova-9 [17]

Answer: $5.81\times 10^6J/mol$

Explanation:

Heat of combustion is the amount of heat released when 1 mole of the compound is completely burnt in the presence of oxygen.

$C_{12}H_{22}O_{11}(s)+12O_2\rightarrow 12CO_2(g)+11H_2O(g)$

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{0.05392g}{342g/mol}=1.577\times 10^{-4}moles$

Thus $1.577\times 10^{-4}moles$ of sucrose releases = 916.6 J of heat

1 mole of sucrose releases = $\frac{916.6}{1.577\times 10^{-4}}\times 1=5.81\times 10^6J$ of heat

Thus ∆H value for the combustion reaction is $5.81\times 10^6J/mol$

6 0

4 years ago

Water exists in liquid form between its 1. Freezing and Boiling point 2. Freezing and melting point 3. Boiling and melting point

Zigmanuir [339]

Answer:

Freezing and boiling point

Explanation:

A liquid form of any substance is an intermediate form between the solid form and the gaseous form.

Decreasing the temperature of liquid water according to the phase diagram of $H_2O$ would freeze it and we would have a phase change from liquid to solid (ice) at the freezing point of water.

Similarly, heating water to its boiling point would evaporate water and we would have a phase change from liquid to gas (water vapor).

Therefore, liquid water exists between its freezing and boiling point.

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3 years ago

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liberstina [14]

Answer:

Explanation:

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3 years ago