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3 years ago

Plz help me I am!!!!

Chemistry

2 answers:

Soloha48 [4]3 years ago

8 0

Gravity forces earth to move around the sun so A

Triss [41]3 years ago

6 0

It’s A. Gravity because of the suns gravitational pull

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What is the average atomic mass of chlorine if the mass of one isotope is 34.97 amu and has a p?er cent abundance of 75.77%. The

pishuonlain [190]

Answer : The average atomic mass of chlorine is, 32.37 amu

Explanation :

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$

As we are given that,

Mass of isotope 1 = 34.97 amu

Percentage abundance of isotope 1 = 75.77 %

Fractional abundance of isotope 1 = 0.7577

Mass of isotope 2 = 36.97 amu

Percentage abundance of isotope 2 = 24.23 %

Fractional abundance of isotope 2 = 0.2423

Now put all the given values in above formula, we get:

$\text{Average atomic mass of element}=\sum[(34.97\times 0.7577)+(24.23\times 0.2423)]$

$\text{Average atomic mass of element}=32.37amu$

Therefore, the average atomic mass of chlorine is, 32.37 amu

8 0

3 years ago

Consider the balanced reaction

Zina [86]

Answer:

Moles of sodium = 15.0⋅g22.99⋅g⋅mol−1 = 0.652⋅mol . Given the stoichiometry of the reaction, clearly 0.652⋅mol sodium hydroxide will result.

Explanation:

please mark me

8 0

3 years ago

Classify each reaction as spontaneous or nonspontaneous. drag the appropriate items to their respective bins.

riadik2000 [5.3K]

Spontaneous reaction is a reaction which occurs naturally that is it has capability of proceeding in a given direction without the use of outside source of energy, while non spontaneous reaction is a reaction which require outside source of energy.drag of the appropriate item to their respective bins is a non spontaneous reaction since outside of energy is required to drag the item.

7 0

3 years ago

Hydrogen can be extracted from natural gas according to the following equilibrium.

antiseptic1488 [7]

Answer:

2.16x10⁻²

Explanation:

First, let's find out the molar concentrations of the reactants. The molar mass of CH4 is 16 g/mol, and of CO2 is 44 g/mol. The number of moles is the mass divided by the molar mass:

nCH4 = 24.0/16 = 1.5 moles

nCO2 = 88.0/44 = 2 moles

The concentration is the number of moles divded by the volume, thus:

[CH4] = 1.5/1 = 1.50 M

[CO2] = 2/1 = 2.00 M

For the equilibrium reaction, let's do an equilibrium chart:

CH4(g) + CO2(g) ⇄ 2CO(g) + 2H2(g)

1.50 2.00 0 0 Initial

-x -x +2x +2x Reacts (stoichiometry is 1:1:2:2)

1.50-x 2.00-x 2x 2x Equilibrium

As sateted in problem, [CH4] = 2.70*[CO]

1.50 - x = 2.70*2x

1.50 - x = 5.4x

6.4x = 1.50

x = 0.2344

Thus, at equilibrium:

[CH4] = 1.50 - 0.2344 = 1.2656 M

[CO2] = 2.00 - 0.2344 = 1.7656 M

[CO] = 2*0.2344 = 0.4688 M

[H2] = 2*0.2344 = 0.4688 M

The equilibrium constant is the multiplication of the concentrations of the products elevated by their coefficients, divided by the multiplication of the concentration of the reactants elevated by their coefficients.

K = ([CO]²*[H2]²)/([CH4]*[CO2])

K = (0.4688²*0.4688²)/(1.2656*1.7656)

K = 0.0483/2.2345

K = 2.16x10⁻²

7 0

3 years ago

A rock contains 0.623 mg of 206Pb for every 1.000 mg of 238U present. Assuming that no lead was originally present, that all the

maxonik [38]

Answer:

t = 3,496x10⁹ years

Explanation:

The decay of ²³⁸U is:

²³⁸U → ²⁰⁶Pb + 8He + 6e⁻

Moles of ²⁰⁶Pb presents in 0,623mg are:

0,623x10⁻³g×(1mol / 206g) = 3,02x10⁻⁶ moles of ²⁰⁶Pb.

These moles are equals to moles of ²³⁸U before decay, that means, 3,02x10⁻⁶ moles²³⁸U

In grams:

3,02x10⁻⁶ moles²³⁸U× (238g / 1mol) = 7,20x10⁻⁴ g ²³⁸U = 0,720 mg²³⁸U

That means initial ²³⁸U was 1,000mg + 0,720mg = 1,720mg

Applying the formula:

ln (N₀/N) t₁₂ = t ln2

Where N₀ is initial amount of uranium (1,720mg), N is concentration of uranium (1,000mg), half-life time is a constant (t₁₂= 4,468x10⁹ years) and t is the time transcurred for the reaction. Replacing:

ln(1,720/1)*4,468x10⁹ years = t ln2

t = 3,496x10⁹ years

I hope it helps!

6 0

3 years ago