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3 years ago

What is the mass of 1 mole of lithium? 6.94 grams 0.432 grams 3.0 grams 2.31 grams

Chemistry

2 answers:

mylen [45]3 years ago

6 0

6.94, the mass of just 1 mole of an element is just the molar mass

ludmilkaskok [199]3 years ago

3 0

Answer:

6.94 grams

Explanation:

n=m/M

m=n·M

m=1·6.94=6.94

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What occurs when zero visibility is caused by heavy snowfall combined strong updrafts and downdrafts

muminat

A whiteout occurs when strong updrafts and downdrafts combine

4 0

4 years ago

Read 2 more answers

Acetylene is hyrodgenated to form ethane. The feed to the reactor contains 1.60 mol H2/mol C2H2. The reaction proceeds to comple

Black_prince [1.1K]

Answer:

Explanation:

C₂H₂ + 2H₂ = C₂H₆

1 mole 2 mole 1 mole

Feed of reactant is 1.6 mole H₂ / mole C₂H₂

or 1.6 mole of H₂ for 1 mole of C₂H₂

required ratio as per chemical reaction written above

2 mole of H₂ for 1 mole of C₂H₂

So H₂ is in short supply . Hence it is limiting reagent .

1.6 mole of H₂ will react with half of 1.6 mole or .8 mole of C₂H₂ to form .8 mole of C₂H₆

a )Calculate the stoichiometric reactant ratio = mole H₂ reacted/mole C₂H₂ reacted

= 1.6 / .8 = 2 .

b )

yield ratio = mole C₂H₆ formed / mole H₂ reacted ) = 0.8 / 1.6 = 1/2 = 0.5 .

4 0

3 years ago

Determine the percent ionization of a 0.225 M solution of benzoic acid. Express your answer using two significant figures.

Assoli18 [71]

Answer:

1.68% is ionized

Explanation:

The Ka of benzoic acid, C₇H₆O₂, is 6.46x10⁻⁵, the equilibrium in water of this acid is:

C₇H₆O₂(aq) + H₂O(l) ⇄ C₇H₅O₂⁻(aq) + H₃O⁺(aq)

Ka = 6.46x10⁻⁵ = [C₇H₅O₂⁻] [H₃O⁺] / [C₇H₆O₂]

<em>Where [] are concentrations in equilibrium</em>

In equilibrium, some 0.225M of the acid will react producing both C₇H₅O₂⁻ and H₃O⁺, the equilibrium concentrations are:

[C₇H₆O₂] = 0.225-X

[C₇H₅O₂⁻] = X

[H₃O⁺] = X

Replacing:

6.46x10⁻⁵ = [X] [X] / [0.225-X]

1.4535x10⁻⁵ - 6.46x10⁻⁵X = X²

1.4535x10⁻⁵ - 6.46x10⁻⁵X - X² = 0

Solving for X:

X = -0.0038. False solution, there is no negative concentrations.

X = 0.00378M. Right solution.

That means percent ionization (100 times Amount of benzoic acid ionized over the initial concentration of the acid) is:

0.00378M / 0.225M * 100 =

<h3>1.68% is ionized</h3>

8 0

3 years ago

The half-life of sr-90 is 28 years. after 56 years of decay only 0. 40 g of a sample remains. what was the mass of the original

Svetradugi [14.3K]

Half-life is the time taken for the concentration of the substance to reduce by 50%. The original sample of strontium had a mass of 1.6 gms. Thus, option d is correct.

The half-life of any radioactive substance is the time period at which the concentration will get reduced to half the initial amount. The initial mass of Sr-90 is calculated as,

$N(t) = N_{0} (\dfrac{1}{2})^{ \frac{t }{t 1/2}}$

Given,

Quantity of the remaining substance N (t) = 0.40 gm

Initial radioactive substance quantity $N_{0}$ =?

Time duration (t) = 56 years

Half-life = 28 years

Substituting values above:

$\begin{aligned} 0.40 &= N_{0} (\dfrac{1}{2}) ^{{\frac{56}{28}}\\\\0.40 &= N_{0} (\dfrac{1}{2})^{2}\end{aligned}$

= 1.6 gm

Therefore, option d. the initial mass of Sr is 1.6 gm.

Learn more about half-life here:

brainly.com/question/16145921

#SPJ4

7 0

2 years ago

Perform the following calculation, 39 / 24.2 . The answer rounded to the correct number of significant figures is which of the f

levacccp [35]

Answer:

Hey!

39 / 24.2 = 943.8

Explanation:

943.8 to 2 s.f (best option for rounding)

= 940

ANSWER = 940

HOPE THIS HELPS!

4 0

3 years ago