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Vera_Pavlovna [14]
3 years ago
8

Select all the correct answers,

Chemistry
1 answer:
Anastasy [175]3 years ago
7 0

Answer:

The reaction for which ΔH is positive are endothermic reactions.

Explanation:

The energy changes occur during the bonds formation and bonds breaking.

There ere two types of reaction endothermic and exothermic reaction.

Endothermic reactions:

The type of reactions in which energy is absorbed are called endothermic reactions.

In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.

For example:

C + H₂O   →  CO  + H₂

ΔH = +131 kj/mol

it can be written as,

C +  H₂O  + 131 kj/mol  →  CO  + H₂

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3.65 gram of hcl is dissolved in 180 gram of water. Find the total number of molecules of hydrogen​
Morgarella [4.7K]

Answer:

Molec_{\ H_{tot}}=1.206x10^{25}molec

Explanation:

Hello.

In this case, taking into account that HCl has one molecule of hydrogen per mole of compound which weights 36.45 g/mol, we compute the number of molecules of hydrogen in hydrochloric acid by considering the given mass and the Avogadro's number:

molec_{\ H}=3.65gHCl*\frac{1molHCl}{36.45gHCl} *\frac{1molH}{1molHCl}*\frac{6.022x10^{23}molec_\ H}{1molH}  =6.03x10^{22}molec

Now, from the 180 g of water, we see two hydrogen molecules per molecule of water, thus, by also using the Avogadro's number we compute the molecules of hydrogen in water:

molec_{\ H}=180gH_2O*\frac{1molH_2O}{18gH_2O} *\frac{2molH}{1molH_2O}*\frac{6.022x10^{23}molec_\ H}{1molH}  =1.20x10^{25}molec

Thus, the total number of molecules turns out:

Molec_{\ H_{tot}}=6.03x10^{22}+1.20x10^{25}\\\\Molec_{\ H_{tot}}=1.206x10^{25}molec

Regards.

6 0
3 years ago
Is the answer B? Help
Masja [62]

Answer:

A

Explanation:

Hmm, so we have the following in the diagram

Pt(s)

Cl2(g)

Ag(s)

NaCl(aq)

AgNO3(aq)

Pt 2+, 4+, 6+  Though it states Pt is inert

Cl 2-

Ag 1+

Na 1+

NO3-

Anode definition: the positively charged electrode by which the electrons leave an electrical device.

Electrode definition: a conductor through which electricity enters or leaves an object, substance, or region.

Cations attracted to cathode pick up electrons

Anions attracted to anode release electrodes+

Reduction at Cathode (red cat gain of e)

Oxidation at Anode (ox anode loss of e)

So from the diagram we can see that the charge is being generated through the 2 metal plates.

So the answer is A, the anode material is Pt and the half reaction is 2Cl- = Cl2 + 2e-

7 0
3 years ago
What is the correct formula for calcium phosphate?
coldgirl [10]
<span>your answer is Ca3</span>(PO4)2<span>, </span>
6 0
3 years ago
Weight and mass are essentially the same measurements.<br> True or false?
Serhud [2]

The answer to this question is False

7 0
3 years ago
Read 2 more answers
I WILL MARK YOU BRAINLIST PLEASE HELP
tekilochka [14]

Answer:  See below

Explanation:  a.  The mass of an element is composed of:

protons:     1 amu each

neutrons:   1 amu each

electrons:   0 amu each

Only the protons and neutrons are counted in the atomic mass of an element

b.  Electrons are assigned a mass of 0.  They do have a mass, but it is exceedingly small compared to the protons and neutrons, so they are left out of the calculation of an element's mass.

c.  An element becomes unstable if the neutrons exceed the protons by a certain ratio, dependent on the element.

7 0
2 years ago
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