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2 years ago

What mass of Na2SO4 is needed to make 2.5L of 2.0M solution? (Na=23g; S=32g; O=16g)

2 answers:

8 0

The molar mass of Na₂SO₄ -
2 x Na - 2 x23 = 46
1 x S - 1 x 32 = 32
4 x O - 4 x 16 = 64
total = 46 + 32 + 64 = 142 g/mol
the molarity of solution - 2.0 M
in 1 L of solution , 2.0 moles
Therefore in 2.5 L - 2 mol/L x 2.5 L = 5 mol
then the mass of Na₂SO₄ required = 142 g/mol x 5 mol = 710 g

Mrac [35]2 years ago

3 0

Answer:

710

Explanation:

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The flame produced by the burner of a gas (propane) grill is a pale blue color when enough air mixes with the propane (C3H8) to

adelina 88 [10]

Answer:

At the burner temp. and pressure, 18.85 litres of air is needed to completely combust each gram of propane

Explanation:

The combustion stoichiometry is as follows:

C₃H₈ + 5O₂ = 4 H₂O + 3CO₂ The molecular weights (g/mol) are:

MW 44 5x32 4x18 3x44

So each gram of propane is 1/44 = 0.02272 mol propane

and will need 5 x 0.02272 = 0.1136 mol oxygen

At 0.21 mol fraction oxygen in air, 0.1136 / 0.21 = 0.54 mol air is needed to burn the propane.

At the low pressure in the burner we can use the Ideal Gas Law

PV=nRT, or V = nRT/P

P = 1.1 x 101325 Pa = 111457 Pa

T = 195°C + 273 = 468 K

R = 8.314

and we calculated n = number of moles air = 0.54 mol

So V m³ = 0.54 x 8.314 x 468 / 111457 = 0.0188 m³ = 18.85 litres air.

6 0

2 years ago

In a fixed cylinder are 3moles of oxygen gas at 300Kelvin and 1.25atm. What is the volume of the container?

vladimir2022 [97]

Answer:

The volume of the container is 59.112 L

Explanation:

Given that,

Number of moles of Oxygen, n = 3

Temperature of the gas, T = 300 K

Pressure of the gas, P = 1.25 atm

We need to find the volume of the container. For a gas, we know that,

PV = nRT

V is volume

R is gas constant, R = 0.0821 atm-L/mol-K

So,

$V=\dfrac{nRT}{P}\\\\V=\dfrac{3\ mol\times 0.0821\ L-atm/mol-K \times 300\ K}{1.25\ atm}\\\\V=59.112\ L$

So, the volume of the container is 59.112 L

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2 years ago

Consider the reaction. 2c(s,graphite) h2= c2h2(g) Based on the equation and the information in the table, what is the enthalpy o

xxTIMURxx [149]

<h3>The enthalpy of the reaction : C.226.73 kJ</h3><h3>Further explanation</h3>

Delta H reaction (ΔH) is the amount of heat change between the system and its environment

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)

The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation

Delta H reaction (ΔH) is the difference between product enthalpy and reactant enthalpy (Hp-Hr)

Reaction :

2C + H2 -> C2H2

(ΔH) reaction = (ΔH) product - (ΔH) reactants

(ΔH) reaction = (ΔH) C2H2 - ((ΔH) C + (ΔH) H2)

for free element (ΔH) it has zero value, so (ΔH) C and (ΔH) H2 have zero value

From the available data: Hf (kJ / mol) C2 H2 (g)= 226.73

then

(ΔH) reaction = ΔH) C2H2 - ((ΔH) C + (ΔH) H2)

(ΔH) reaction = 226.73 - (0 + 0)

(ΔH) reaction = 226.73 (answer C)

<h3>Learn more</h3>

(ΔH) reaction

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Keywords : (ΔH) reaction, C2H2

8 0

2 years ago

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Green light has a frequency of about 6.00×1014s−1. What is the energy of a photon of green light?

Sindrei [870]

3.98 x 10⁻¹⁹ Joule

<h3>Further explanation</h3>

<u>Given:</u>

The green light has a frequency of about 6.00 x 10¹⁴ s⁻¹.

<u>Question:</u>

The energy of a photon of green light (in joules).

<u>The Process:</u>

The energy of a photon is given by $\boxed{\boxed{ \ E = hf \ }}$

E = energy in joules
h = Planck's constant 6.63 x 10⁻³⁴ Js
f = frequency of light in Hz (sometimes the symbol f is written as v)

Let us find out the energy of the green light emitted per photon.

$\boxed{ \ E = (6.63 \times 10^{-34})(6.00 \times 10^{14}) \ }$

Thus, we get a result of $\boxed{\boxed{ \ E = 3.98 \times 10^{-19} \ J \ }}$

- - - - - - - - - -

Notes

When an electron moves between energy levels it must emit or absorb energy.
The energy emitted or absorbed corresponds to the difference between the two allowed energy states, i.e., as packets of light called photons.
A higher energy photon corresponds to a higher frequency (shorter wavelength) of light.

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Determine the density of our sun at the end of its lifetime brainly.com/question/5189537
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Keywords: green light, frequency, the energy, a photon, Planck's constant, electrons, emitted, wavelength, joules

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2 years ago

When metals combine with nonmetals, the metallic atoms tend to 1. lose electrons and become positive ions 2. lose electrons and

Vika [28.1K]

The correct answer is 1. Lose electrons and become positive ions.

I hope my answer was beneficial to you! c:

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2 years ago

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