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GrogVix [38]
3 years ago
6

Estimate the heat released when ethene (CH2=CH2) reacts with HBr to give CH3CH2Br.

Chemistry
1 answer:
bonufazy [111]3 years ago
7 0

Answer:

c)

Explanation:

The reaction between ethene and HBr is:

CH2=CH2 + HBr → CH3CH2Br

Thus, the double bond C=C and the bond H-Br were broken, and the bonds C-C, C-H and C-Br were formed. The enthalpy of the reaction (the energy change), is the sum of the enthalpies of the reactions that were broken with the bonds that were created.

To break a bond, it's necessary to the molecule to gain energy, thus the process is endothermic and H>0, and to form a bond, it's necessary to release energy, and so H<0, so:

ΔH = ∑n*Hbroken - ∑n*Hformed, where n is the coefficient of the substance, so:

ΔH = (612 + 366) - (348+412+276)

ΔH  = -58 kJ/mol

The minus signal indicates that the energy was released.

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Political Map. A political map shows the state and national boundaries of a place. ...

Explanation:

3 0
3 years ago
Which element, represented by X, reacts with oxygen to produce the compound X2O?
natali 33 [55]

Answer:

lithium

Explanation:

this is because lithium has a valency of 1 and oxygen has a valency of 2 thereby exchanging valency to create Li²0

7 0
3 years ago
Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolat
zepelin [54]

Answer:

The correct answer is 0.12 grams.

Explanation:

The mass of carbon monoxide or CO collected in the tube can be determined by using the ideal gas equation, that is, PV = nRT.

Based on the given question, P or the pressure of the gas is given as 1 atm, volume of the gas collected in the tube is 117 ml or 0.117 L.  

The number of moles or n can be determined by using the equation, mass/molar mass.  

R is the universal gas constant, whose value is 0.0821 L atmK^-1mol^-1, and temperature is 55 degree C or 328 K (55+273).  

On putting the values we get:

n = PV/RT

= (1 atm*0.117 L) / (0.0821 L atmK^-1mol^-1 * 328 K)

= 0.0043447 mol

Therefore, mass of CO will be moles * molar mass of CO

= 0.0043447 mol * 28 g/mol

= 0.12 g

3 0
3 years ago
The​ half-life of a certain tranquilizer in the bloodstream is 5050 hours. how long will it take for the drug to decay to 8686​%
Novosadov [1.4K]
Using the exponential decay model; we calculate "k"
We know that "A" is half of A0
A = A0 e^(k× 5050)
A/A0 = e^(5050k)
0.5 = e^(5055k)
In (0.5) = 5055k 
-0.69315 = 5055k
 k = -0.0001371
To calculate how long it will take to decay to 86% of the original mass
0.86 = e^(-0.0001371t)
In (0.86) = -0.0001371t
-0.150823 = -0.0001371 t
 t = 1100 hours

4 0
3 years ago
Consider the chemical equations shown here.
vichka [17]

P₄0₆_{s} + 20₂_{g}   ⇒    P₄0₁₀_{s}

Explanation:

The overall equation for the reaction that produces  P₄0₁₀ is :

P₄0₆_{s} + 20₂_{g}   ⇒    P₄0₁₀_{s}

Now let us derive this equation:

Given equations:

   P₄_{s} + 30₂_{g}  ⇒ P₄0₆_{s}  equation 1;

   P₄_{s} + 50₂_{g} ⇒  P₄0₁₀_{s}  equation 2;

To get the overall combined equation, the equation 1 must be reversed and added to equation 2:

            P₄0₆_{s} ⇒ P₄_{s} + 30₂_{g}   equation 3

                      +

            equation 2:

 P₄_{s} + 50₂_{g}  +    P₄0₆_{s}  ⇒  P₄0₁₀_{s}  +  P₄_{s} + 30₂_{g}  

cancelling specie that appears on both sides and removing excess oxygen gas on the reactant side gives;

   

                  P₄0₆_{s} + 20₂_{g}   ⇒    P₄0₁₀_{s}

learn more:

Net equation brainly.com/question/2947744

#learnwithBrainly

5 0
3 years ago
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