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denis23 [38]
3 years ago
8

Which is the most important question for deciding if a chemical reaction has occurred?

Chemistry
2 answers:
777dan777 [17]3 years ago
7 0

Answer:

all these are physical properties except release of heat so it's probably heat energy given off

navik [9.2K]3 years ago
4 0

Answer:Was any heat energy given off?

Explanation:

A chemical reaction may exothermic (heat is given off) or endothermic (heat is absorbed). Size, density or texture of the substance are strictly physical properties which cannot confirm that a chemical reaction has transpired in the sample. The evolution of heat ultimately confirms that a chemical process has taken place.

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Which of the following is a mixture? <br> Water (H2O), Gold, or Kool-Aid
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Sugar is an example of a compound, while koolaid is an example of a homogeneous mixture (more specifically, a solution). A compound is a combination of 2 or more different kinds of atoms chemically bonded in a set ratio. A mixture is a combination of 2 or more substances.

answer is koolaid is a mixture

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Why can’t an atom lose or gain a proton
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Explanation:

Atoms never gain protons; they become positively charge only by losing electrons. A positive ion is called a cation (pronounced: CAT-eye-on). You may have notice that the number of neutrons in each of these ions was not specified.

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PLEASE HURRY AND CHECK IMMAGE. Predict the shape of the molecule.
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A. bent

Explanation:

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C6H12O6 is the formula for a sugar molecule.molecules are classified as?
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2 years ago
How much energy must be removed from a 94.4 g sample of benzene (molar mass= 78.11 g/mol) at 322.0 K to solidify the sample and
Kay [80]

Answer : The energy removed must be, 29.4 kJ

Explanation :

The process involved in this problem are :

(1):C_6H_6(l)(322K)\rightarrow C_6H_6(l)(279K)\\\\(2):C_6H_6(l)(279K)\rightarrow C_6H_6(s)(279K)\\\\(3):C_6H_6(s)(279K)\rightarrow C_6H_6(s)(205K)

The expression used will be:  

Q=[m\times c_{p,l}\times (T_{final}-T_{initial})]+[m\times \Delta H_{fusion}]+[m\times c_{p,s}\times (T_{final}-T_{initial})]

where,

Q = heat released for the reaction = ?

m = mass of benzene = 94.4 g

c_{p,s} = specific heat of solid benzene = 1.51J/g^oC=1.51J/g.K

c_{p,l} = specific heat of liquid benzene = 1.73J/g^oC=1.73J/g.K

\Delta H_{fusion} = enthalpy change for fusion = -9.8kJ/mol=-\frac{9.8\times 1000J/mol}{78g/mol}=-125.6J/g

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

Q=[94.4g\times 1.73J/g.K\times (279-322)K]+[94.4g\times -125.6J/g]+[94.4g\times 1.51J/g.K\times (205-279)K]

Q=-29427.312J=-29.4kJ

Negative sign indicates that the heat is removed from the system.

Therefore, the energy removed must be, 29.4 kJ

3 0
3 years ago
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