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laila [671]
3 years ago
5

Why is measuring the size of an atom difficult

Chemistry
1 answer:
vlada-n [284]3 years ago
5 0
<span>Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. Atomic size is difficult to measure because it has no definite boundary. The electrons surrounding the nucleus exist in an electron cloud.
</span>
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Identify the substances that will appear in the equilibrium constant expression for the equation: 2Ag+(aq)+Zn(s)&lt;-&gt;Zn2+(aq
Simora [160]

Hey there!


We Know that:



 2 Ag⁺(aq) + Zn(s) <-> Zn²⁺(aq)+2 Ag(s)


The equilibrium expression for the reaction is:



Kc =  [ Zn⁺² ]  /  [Ag⁺ ]²


Hope that helps!

8 0
3 years ago
Read 2 more answers
A chemist measures the enthalpy change ?H during the following reaction: Fe (s) + 2HCl (g) ? FeCl2 (s) + H2 (g) =?H?157.kJ Use t
erik [133]

Correct Question:

A chemist measures the enthalpy change ΔH during the following reaction: Fe(s) + 2HCl(g)-->FeCl2(s) + H2 ΔH=-157.0 kJ. Use this information to complete the table below. Round each of your answers to the nearest kJ/mol

Answer:

-314 kJ

+628 kJ

+157 kJ

Explanation:

The enthalpy change of a reaction measures the amount of heat that is lost or gained by it. If ΔH >0 the heat is gained, and the reaction is called endothermic, if ΔH<0, the heat is lost, and the reaction is called exothermic.

If the reaction is inverted, the value of ΔH is inverted too (the opposite endothermic reaction is exothermic), and if the reaction is multiplied by a constant, ΔH will be multiplied by it too.

1) 2Fe(s) + 4HCl --> 2FeCl2(s) + 2H2(g)

This reaction is the product of the given reaction by 2, so

ΔH = 2*(-157) = -314 kJ

2) 4FeCl2(s) + 4H2(g) --> 4Fe(s) + 8HCl(g)

This reaction is the inverted reaction given multiplied by 4, so

ΔH = 4*(157) = +628 kJ

3) FeCl2(s) + H2(g) --> Fe(s) + 2HCl

This reaction is the inverted reaction given, so

ΔH = +157 kJ

4 0
3 years ago
1. What are the two effects of the continental plate/continental plate convergent boundary?
weeeeeb [17]

Answer:

Answer 1: The correct answer is b. convergent continental-continental boundary.

A convergent continental-continental boundary refers to a convergent plate boundary where two continental plates meet or come together. When this happens, a forceful collision occurs, and structures like mountains start to form. The Himalaya mountain range is formed as a result of the convergence of the Indian and Eurasian continental plates.

Answer 2: The correct answer is d. convergent oceanic-oceanic boundary.

Volcanic island arcs refers to a curved line of volcanoes formed from the subduction (sinking) of one oceanic plate below another plate. Examples of volcanic island arcs include Japanese Islands and Alaskan Islands

8 0
2 years ago
Ammonia NH3 may react with oxygen to form nitrogen gas and water.4NH3 (aq) + 3O2 (g) \rightarrow 2 N2 (g) + 6H2O (l)If 2.15g of
bagirrra123 [75]

Answer:

NH3 is the limiting reactant

The % yield is 36.1 %

Explanation:

<u>Step 1: </u>Data given

Mass of NH3 = 2.15 grams

Mass of O2 = 3.23 grams

Molar mass of NH3 = 17.03 g/mol

Molar mass of O2 = 32 g/mol

volume of N2 produced = 0.550 L

Temperature = 295 K

Pressure = 1.00 atm

<u>Step 2:</u> The balanced equation:

4NH3 (aq) + 3O2 (g) → 2 N2 (g) + 6H2O (l)

<u>Step 3:</u> Calculate moles of NH3

Moles NH3 = Mass NH3 / Molar Mass NH3

Moles NH3 = 2.15 grams / 17.03 g/mol

Moles NH3 = 0.126 moles

<u>Step 4:</u> Calculate moles of O2

Moles O2 = 3.23 grams / 32 g/mol

Moles O2 = 0.101 moles

<u>Step 5: </u>Calculate the limiting reactant

For 4 moles NH3 consumed, we need 3 moles of O2 to produce, 2 moles of N2 and 6 moles of H2O

NH3 is the limiting reactant. It will completely be consumed ( 0.126 moles).

O2 is in excess, there will be 3/4 * 0.126 = 0.0945 moles consumed

There will remain 0.101 - 0.945 = 0.0065 moles of O2

<u>Step 6:</u> Calculate moles of N2

For 4 moles NH3 consumed, we need 3 moles of O2 to produce, 2 moles of N2 and 6 moles of H2O

For 4 moles NH3 , we'll have 2 moles of N2 produced

For 0.126 moles NH3 consumed, we'll have 0.063 moles of N2 produced.

<u>Step 7</u>: Calculate volume of N2 produced

p*V = n*R*T

⇒ with p = the pressure of the gas = 1.00 atm

⇒ with V = the volume = TO BE DETERMINED

⇒ with n = the number of moles N2 = 0.063 moles

⇒ with R = the gasconstant = 0.08206 L*atm/K*mol

⇒ with T = the temperature = 295

V = (nRT)/p

V = (0.063*0.08206*295)/1

V = 1.525 L = theoretical yield

<u>Step 8:</u> Calculate the % yield

% yield = actual yield / theoretical yield

% yield = (0.550 L / 1.525 L)*100%

% yield = 36.1 %

4 0
3 years ago
What does it mean for a reaction to release energy?.
8090 [49]

Answer:

exothermic

Explanation:

4 0
2 years ago
Read 2 more answers
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