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3 years ago

Which image(s) would be considered pure substances? A) V B) I and II C) II and IV D) III and V

Chemistry

2 answers:

Nata [24]3 years ago

7 0

V is the answer for this question

Blizzard [7]3 years ago

6 0

The answer is V but i could be wrong

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the molar solubility of Zn(OH)2 is 5.7x 10^-3 mol/L at a certain temperature. Calculate the value of Ksp for Zn(OH)2 at this tem

Alex

Answer:

Ksp = 7.4x10⁻⁷

Explanation:

Molar solubility of a substance is defined as the amount of moles of that can be dissolved per liter of solution.

Ksp of Zn(OH)₂ is:

Zn(OH)₂(s) ⇄ Zn²⁺ + 2OH⁻

Ksp = [Zn²⁺] [OH⁻]²

And the molar solubility, X, is:

Zn(OH)₂(s) ⇄ Zn²⁺ + 2OH⁻

⇄ X + 2X

<em>Because X are moles of substance dissolved.</em>

<em>Ksp = </em>[X] [2X]²

Ksp = 4X³

As molar solubility, X, is 5.7x10⁻³mol/L:

Ksp = 4X³

Ksp = 4 (5.7x10⁻³mol/L)³

5 0

3 years ago

Several kinds of bears are found on Earth. Most bears are brown or black, but one type of bear, the polar bear, is white. What p

jeka94

This is called adaptation. An example would be a polar bear with white fur. They have this to be more efficent hunters, as they use it as a type of camouflage in order to sneak up on prey. Brown bear use this in the same way but their environment requires them to be brown in order to blend in beter with trees. So basicly adaptation

7 0

3 years ago

Read 2 more answers

Given the equation 2mg(s) + o2(g) → 2mgo(s) + 72.3 kj, how much heat is involved in the production of 5.0 mol of mgo? question 2

Rudik [331]

The heat is involved in the production of 5.0 mol of MgO is 180 Kj

   calculation

2 Mg (s) +O2 → 2 MgO

From the equation above two moles of MgO is used therefore

72.3 is for 2 moles

that is 72.3 kj = 2moles
? = 5 moles

by cross multiplication

= 72.3 kj × 5/2 = 180 Kj

7 0

3 years ago

A key step in balancing chemical equations is correctly identifying the formulas of the reactants and products. For example, con

icang [17]

Answer:

CaO + H2O= Ca(OH)2

Explanation:

The rule of balancing chemical equation states that the total number of atoms an element on the right hand side, must equal the total number of atoms of the same element on the left hand side of the reaction equation. This rule is satisfied in the equation above. For example, there are two oxygen atoms at the RHS and two at the LHS.

6 0

3 years ago

For an enzyme that displays Michaelis-Menten kinetics, what is the reaction velocity, v(as a percentage of Vmax), observed at:a)

fiasKO [112]

Answer:

a) 50% of the maximum velocity

b) 33.33% of the maximum velocity

c) 9.09% of the maximum velocity

d) 66.66% of the maximum velocity

e) 90.9% of the maximum velocity

Explanation:

The Michaelis-Menten kinetis is represented by

v = Vmax*S/(Km+S)

where

v= reaction rate

S= Substrate's concentration

Vmax= maximum rate of reaction

Km= constant

a) for S=Km

v = Vmax*Km/(2Km) = Vmax/2

v/Vmax = 1/2= 50% of the maximum velocity

b) for S=Km/2

v = Vmax*(Km/2)/(3/2Km) = Vmax/3

v/Vmax = 1/3= 33.33% of the maximum velocity

c) for S= 0.1*Km=Km/10

v = Vmax*(Km/10)/(11/10Km) = Vmax/11

v/Vmax = 1/11= 9.09% of the maximum velocity

d) for S=2*Km

v = Vmax*(2*Km)/(3*Km) = (2/3)* Vmax

v/Vmax = 2/3 = 66.66% of the maximum velocity

d) for S=10*Km

v = Vmax*(10*Km)/(11*Km) = (10/11)* Vmax

v/Vmax = 10/11 = 90.9 % of the maximum velocity

7 0

4 years ago