What the answer I’m on a midterm and can’t seem to find it help

Which reactant will be in excess, and how many moles of it will be left over?

timofeeve [1]

Answer:

Oxygen with 0.36 moles left over

Explanation:

5 0

3 years ago

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Consider the following reaction:

PIT_PIT [208]

Answer:

Kc = 3.1x10²

Explanation:

At equilibrium, the velocity of product formation is equal to the velocity of reactants formation. For a generic reaction, the equilibrium constant (Kc) is:

aA + bB ⇄ cC + dD

$Kc = \frac{[C]^c*[D]^d}{[A]^a*[B]^b}$

Where [X] is the molar concentration of X, and the solid substances are not considered (because it's activity is 1, for the other substances, the activity is substituted for the molar concentration, which forms the equation above).

For the reaction given, let's make an equilibrium chart:

Fe³⁺(aq) + SCN⁻(aq) ⇄ FeSCN²⁺(aq)

1.1*10⁻³ 8.2*10⁻⁴ 0 Initial

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

1.1*10⁻³ -x 8.2*10⁻⁴ -x x Equilibrium

x = 1.8*10⁻⁴ M, so the molar concentrations at equilibrium are:

[Fe⁺³] = 1.1*10⁻³ - 1.8*10⁻⁴ = 9.2*10⁻⁴ M

[SCN⁻] = 8.2*10⁻⁴ - 1.8*10⁻⁴ = 6.4*10⁻⁴ M

[FeSCN⁺²] = 1.8*10⁻⁴ M

Kc = [FeSCN⁺²]/([Fe⁺³]*[SCN⁻])

Kc = (1.8*10⁻⁴)/(9.2*10⁻⁴*6.4*10⁻⁴)

Kc = 306 = 3.1x10²

6 0

3 years ago

How many reactant molecules and product gas molecules are in this equation?

Mice21 [21]

Answer:

N₂ = 6.022 × 10²³ molecules

H₂ = 18.066 × 10²³ molecules

NH₃ = 12.044 × 10²³ molecules

Explanation:

Chemical equation;

N₂ + 3H₂ → 2NH₃

It can be seen that there are one mole of nitrogen three mole of hydrogen and two moles of ammonia are present in this equation. The number of molecules of reactant and product would be calculated by using Avogadro number.

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

Number of molecules of nitrogen gas:

1 mol = 6.022 × 10²³ molecules

Number of molecules of hydrogen:

3 mol × 6.022 × 10²³ molecules/ 1 mol

18.066 × 10²³ molecules

Number of molecules of ammonia:

2 mol × 6.022 × 10²³ molecules/ 1 mol

12.044 × 10²³ molecules

6 0

4 years ago

Working on-board a research vessel somewhere at sea, you have (carefully) isolated 12.5 micrograms (12.5 ×10–6 g) of what you ho

german

Answer:

The value is $Z = 311.33 \ g/mol$

Explanation:

From the question we are told that

The mass of saxitoxin is $m = 12.5 mg = 12.5 * 10^{-6} g$

The volume of water is $V = 3.10 mL = 3.10 *10^{-3} L$

The osmotic pressure is $P = 0.236 = \frac{0.236}{760} = 3.105 * 10^{-4} atm$

The temperature is $T = 19^oC = 19 + 273 = 292 \ K$

Generally the osmotic pressure is mathematically represented as

$P = C * T * R$

Here R is the gas constant with value

$R = 0.0821 ( L .atm /mol. K)$

and C is the concentration of saxitoxin

So

$3.105 * 10^{-4} = C * 0.0821 * 292$

$C = 1.295 *10^{-5} mol/L$

Generally the number of moles of saxitoxin is mathematically represented as

$n = C * V$

=> $n = 1.295 *10^{-5} *3.10 *10^{-3}$

=> $n = 4.015 *10^{-8} \ mol$

Generally the molar mass of saxitoxin is mathematically represented as

$Z = \frac{m}{n}$

=> $Z = \frac{12.5 * 10^{-6}}{ 4.015 *10^{-8}}$

=> $Z = 311.33 \ g/mol$

5 0

4 years ago

What type of footwear protects your toes from falling objects and being crushed?

Margaret [11]

The correct option is D.

Engineers and constructions workers have different types of footwear, which they make use of when they are in the field. Each of these foot wears has its own purpose and functions. For instance, the steel toe boots serve to protect the foot from falling falling objects and also from compression. The foot wear has a protective support in the toe and also possesses a mid sole plate to protect the foot again puncture from the sole.

4 0

3 years ago

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