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3 years ago

Determine the number of representative particles in each of the following:

Chemistry

1 answer:

tia_tia [17]3 years ago

3 0

Answer:

(a) 0.294 mol silver = $1.770 * 10^{23}$

(b) 8.98 * 10-3 mol sodium chloride - $5.407 *10^{23}$

(d) 0.310 mol nitrogen (N2) = $1.866 * 10^{23}$

Explanation:

In one mole there are $6.022 * 10^{23}$ atoms/molecules

(a) 0.294 mol silver = $6.022 * 10^{23} * 0.294 = 1.770 * 10^{23}$

(b) 8.98 * 10-3 mol sodium chloride - $5.407 *10^{23}$

(d) 0.310 mol nitrogen (N2) = $0.310 * 6.022 * 10^{23} = 1.866 * 10^{23}$

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23.13 grams divided by 35.0 mL?

jonny [76]

660.857143 kg / m3, I think and idk if it's rounded

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3 years ago

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A 6.53 g sample of a mixture of magnesium carbonate and calcium carbonate is treated with excess hydrochloric acid. The resultin

Advocard [28]

Answer:

0.069moles

45.65%

Explanation:

Firstly, we need to calculate the number of moles of CO2 produced. We can use the ideal gas equation for this.

PV = nRT

n = PV/RT

according to the question,

P = 746torr

V = 1.73L

T = 26 = 26 + 273.15 = 299.15K

n = ?

R = 62.364 L. Torr/k.mol

n = (746 * 1.73)/(62.364 * 299.15) = 0.069moles

B. To get this, we can use their molar masses. The molar mass of calcium carbonate is 100g/mol while for magnesium carbonate, molar mass is 84g/mol

The percentage by mass is (84)/(84 + 100) * 6.53g = 2.98g

= 2.98/6.53 * 100 = 45.65%

6 0

4 years ago

The balanced equation for a hypothetical reaction is a 5b 6c → 3d 3e. what is the rate law for this reaction?

Helen [10]

It can not be answered without experimental data.

8 0

3 years ago

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Given the following data:N2(g) + O2(g)→ 2NO(g), ΔH=+180.7kJ2NO(g) + O2(g)→ 2NO2(g), ΔH=−113.1kJ2N2O(g) → 2N2(g) + O2(g), ΔH=−163

statuscvo [17]

Answer:

ΔH = +155.6 kJ

Explanation:

The Hess' Law states that the enthalpy of the overall reaction is the sum of the enthalpy of the step reactions. To do the addition of the reaction, we first must reorganize them, to disappear with the intermediaries (substances that are not presented in the overall reaction).

If the reaction is inverted, the signal of the enthalpy changes, and if its multiplied by a constant, the enthalpy must be multiplied by the same constant. Thus:

N₂(g) + O₂(g) → 2NO(g) ΔH = +180.7 kJ

2NO(g) + O₂(g) → 2NO₂(g) ΔH = -113.1 kJ

2N₂O(g) → 2N₂(g) + O₂(g) ΔH = -163.2 kJ

The intermediares are N₂ and O₂, thus, reorganizing the reactions:

N₂(g) + O₂(g) → 2NO(g) ΔH = +180.7 kJ

NO₂(g) → NO(g) + (1/2)O₂(g) ΔH = +56.55 kJ (inverted and multiplied by 1/2)

N₂O(g) → N₂(g) + (1/2)O₂(g) ΔH = -81.6 kJ (multiplied by 1/2)

------------------------------------------------------------------------------------

N₂O(g) + NO₂(g) → 3NO(g)

ΔH = +180.7 + 56.55 - 81.6

ΔH = +155.6 kJ

5 0

4 years ago

The element antimony has an atomic weight of 122 and consists of two stable isotopes antimony-121 and antimony-123. the isotope

grin007 [14]

Answer:- 123 amu.

Solution:- The formula to calculate the average atomic mass of an atom is:

Average atomic mass = mass of first isotope(abundance of first isotope) + mass of second isotope(abundance of second isotope)

Note: The percent abundance is converted to decimals.

mass of Sb-121 is 121 amu and it's percent abundance is 57.3% and in decimal it is 0.573. Percent abundance of Sb-123 is 42.8% and in decimal it is 0.428. We are asked to calculate it's mass. The average atomic mass of Sb is given as 122.

Let's say the mass of Sb-123 is M and plug in the values in the formula and do calculations:

122 = 121(0.573) + M(0.428)

122 = 69.333 + M(0.428)

On rearrangement:-

M(0.428) = 122 - 69.333

M(0.428) = 52.667

$M=\frac{52.667}{0.428}$

M = 123

So, the mass of Sb-123 is 123 amu.

6 0

4 years ago