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3 years ago

What is the [ H3O+] of a solution with pH = (8.50x10^0)? enter your answer in scientific notation and with three sig figs.

Chemistry

2 answers:

blagie [28]3 years ago

4 0

Answer:

3.17 x 10^-9

Explanation:

log 3.17 =.5 log 10^-9 =-9 .5+-9=-8.5 =pH 8.5

erastovalidia [21]3 years ago

3 0

Answer:

[H₃O⁺] = 3.162 × 10⁻⁹ moles / liter

Explanation:

The pH is calculated with the formula:

pH = -lg[H₃O⁺]

From here the concentration of hydronium ion (H₃O⁺) will be:

[H₃O⁺] = $10^{-pH}$

[H₃O⁺] = $10^{-8.5}$

[H₃O⁺] = 3.162 × 10⁻⁹ moles / liter

You might be interested in

A beaker containing 6.32 moles of PBr3, contains___

NISA [10]

Answer:

3.8 x 10²⁴molecules

Explanation:

Given parameters:

Number of moles = 6.32moles

Unknown:

Number of molecules = ?

Solution:

The number of moles can be used to derive the number of molecules found within a substance.

Now,

1 mole of substance contains 6.02 x 10²³ molecules

6.32 mole of PBr₃ will contain 6.32 x 6.02 x 10²³ = 3.8 x 10²⁴molecules

8 0

3 years ago

Mole conversions.<br> Find the number of moles of argon in 607g of argon?

bogdanovich [222]

Answer:

24249.65 mol

Explanation:

n=MM × m

n= 39.95 ×607

n=24249.65

5 0

3 years ago

5. Durante un estudio de la velocidad de la reacción A2(g) + 3B2(g)  2 AB3(g), se observa que en un recipiente cerrado que cont

weqwewe [10]

Answer:

a) Speed of the reaction = 0.002083 mol/L.s

b) The rate of disappearance of A₂ during this period of time = 0.002083 mol/L.s

c) The rate of appearance of AB₃ = 0.004167 mol/L.s

Explanation:

English Translation

During a study of the reaction rate

A₂ (g) + 3B₂ (g) → 2 AB₃ (g),

it is observed that in a closed container containing a certain amount of A₂ and 0.75 mol / L of B₂, the concentration B₂ decreases to 0.5 mol / L in 40 seconds.

a) What is the speed of the reaction?

b) What is the rate of disappearance of A₂ during this period of time?

c) What is the rate of appearance of AB₃?

Solution

The rate of a chemical reaction is defined as the time rate at which a reactant is used up or the rate at which a product is formed.

It is the rate of change of the concentration of a reactant (rate of decrease of the concentration of the reactant) or a product (rate of increase in the concentration of the product) with time.

Mathematically, for a balanced reaction

aA → bB

Rate = -(1/a)(ΔA/Δt) = (1/b)(ΔB/Δt)

The minus sign attached to the change of the reactant's concentration indicates that the reactant's concentration decreases.

And the coefficients of each reactant and product in the balanced reaction normalize the rate of reaction for each of them

So, for our given reaction,

A₂ (g) + 3B₂ (g) → 2 AB₃ (g)

Rate = -(ΔA₂/Δt) = -(1/3)(ΔB₂/Δt) = (1/2)(ΔAB₃/Δt)

a) Speed of the reaction = Rate of the reaction

But we are given information on the change of concentration of B₂

Change in concentration of B₂ = ΔB₂ = 0.50 - 0.75 = -0.25 mol/L

Change in time = Δt = 40 - 0 = 40 s

(ΔB₂/Δt) = (-0.25/40) = -0.00625 mol/L.s

Rate of the reaction = -(1/3)(ΔB₂/Δt) = (-1/3) × (-0.00625) = 0.002083 mol/L.s

b) The rate of disappearance of A₂ during this period of time

Recall

Rate = -(ΔA₂/Δt) = -(1/3)(ΔB₂/Δt)

-(ΔA₂/Δt) = -(1/3)(ΔB₂/Δt)

Rate of disappearance of A₂ = -(ΔA₂/Δt) = -(1/3)(ΔB₂/Δt) = (-1/3) × (-0.00625) = 0.002083 mol/L.s

c) The rate of appearance of AB₃

Recall

Rate = -(1/3)(ΔB₂/Δt) = (1/2)(ΔAB₃/Δt)

(1/2)(ΔAB₃/Δt) = -(1/3)(ΔB₂/Δt)

(ΔAB₃/Δt) = -(2/3)(ΔB₂/Δt)

rate of appearance of AB₃ = (ΔAB₃/Δt) = -(2/3)(ΔB₂/Δt) = (-2/3) × (-0.00625) = 0.004167 mol/L.s

Hope this Helps!!!

3 0

2 years ago

The teacher tells your group to make a stock solution of sodium chloride, and then diluting it to

sergejj [24]

The idea here is that you need to figure out how many moles of magnesium chloride,

MgCl

, you need to have in the target solution, then use this value to determine what volume of the stock solution would contain this many moles.

As you know, molarity is defined as the number of moles of solute, which in your case is magnesium chloride, divided by liters of solution.

So, how many moles of magnesium chloride must be present in the target solution?

⇒

⋅

0.158 M

⋅

250.0

⋅

−

0.0395 moles MgCl

Now determine what volume of the target solution would contain this many moles of magnesium chloride

⇒

0.0395

moles

3.15

moles

0.01254 L

Rounded to three sig figs and expressed in mililiters, the volume will be

12.5 mL

So, to prepare your target solution, use a

12.5-mL

sample of the stock solution and add enough water to make the volume of the total solution equal to

250.0 mL

This is equivalent to diluting the

12.5-mL

sample of the stock solution by a dilution factor of

3 0

2 years ago

Chris noticed a high-pressure system in the weather forecast for Monday

Alchen [17]

Answer:

A. Clear and Sunny

Explanation:

The answer would be A. Clear and Sunny. A high pressure system occurs where the air mass above the Earth is denser than in surrounding areas, and therefore exerts a higher force or pressure. They usually happen with li9ght winds. Using process of elimination, it could not be D. Warm and Stormy, C. Cloudy and Rainy, or B. Cold and Stormy because all have wet climates.

5 0

2 years ago