All categories

3 years ago

What is the color of the flame when magnesium burns in air

Chemistry

1 answer:

vfiekz [6]3 years ago

6 0

Answer:

Will u give me brainliest

white

In its pure form, it is silvery white, and relatively soft. It burns in air with a brilliant white light, and for this reason is often used in flares and fireworks. Magnesium is used in disposable flash bulbs to generate light for photography, but this use has been largely supplanted by other sources of illumination

You might be interested in

(Atomic masses used are C = 12.0 g mol–1, O = 16.0 g mol–1, H = 1.01 g mol–1, Cu = 63.5 g mol–1,)

alex41 [277]

Question 1

The formula mass of methanol is $12.0+3(1.01)+16.0+1.01=32.04$ g/mol.

Therefore, in 5.0 grams of methanol, there are $5.0/32.04=\boxed{0.16}$ moles.

Question 2

The formula mass of copper(II) carbonate is $63.5+12.0+3(16.0)=123.5$ g/mol.

This means that in 9.0 grams of copper(II) carbonate, there are $9.0/123.5=0.072874493927126$ moles.

Using Avogradro's number, there are $(0.072874493927126)(6.022 \times 10^{23})=\boxed{4.4 \times 10^{22}}$ molecules.

Question 3

The formula mass of cyclohexane is $12.0(6)+1.01(12)=84.12$ g/mol.

So, 3.0 grams of cyclohexane is the same as $3.0/84.12=\boxed{0.036}$ moles.

Question 4

The formula mass of benzene is $12.0(6)+1.01(6)=78.06$ g/mol.

This means that 4.00 moles of benzene has a mass of $(78.06)(4.00)=\boxed{312}$ grams.

Question 5

1000 atoms of calcium is the same as $\frac{1.000}{6.022 \times 10^{23}}$ moles.

This is equal to $\frac{1000}{6.022 \times 10^{23}} \cdot 40.078=\boxed{6.7 \times 10^{-20}}$ grams.

6 0

1 year ago

Which of the following is a reasonable ground-state electron configuration?A) 1s21p62d2B) 1s22s42p6C) 1s22s22p5D) 1s22s22d6

Semenov [28]

Answer:

Option C) 1s² 2s² 2p⁵

Explanation:

Ground-state is the configuration of the electrons when every electron of the atom occupies the lowest possible energy level.

The rank of energy of the orbitals may be remembered using Aufbau rules, and it is:

1s² < 2s² < 2p⁶ < 3s² < 3p⁶ < 4s² < 3d¹⁰ < 4p⁶ < 5s² < 4d¹⁰ < 5p⁶ < 6s² < 4f¹⁴ < 5d¹⁰ < 6p⁶ < 7s² < 5f¹⁴ < 6d¹⁰ < 7p⁶

Then, to find whether an electron configuration corresponds to a ground-state one, you must check that the previous order is preserved.

Option A). 1s² 1p⁶ 2d²

The orbital 1p does not exist. So this one is discarded.

Option B) 1s² 2s⁴ 2p⁶

The maximum number of electrons in an s orbital is 2, so 2s⁴ is impossible, and this option is discarded.

Option C) 1s² 2s² 2p⁵

This is correct because the orbitals are filled in the correct increasing energy order, without jumping any one.

Option D) 1s² 2s² 2d⁶

Orbital 2d does not exist, so this option is also discarded.

4 0

3 years ago

a nickel atom (atomic symbol Ni) has an atomic number of 28 and has an atomic mass of 59. how many neutrons does it have ??

shusha [124]

Answer: 31 neutrons

Explanation:

8 0

3 years ago

What is the molecular weight of one mole of H2CO3? g/mole

eimsori [14]

The answer is 62.026 g/mole

6 0

4 years ago

Read 2 more answers

If 0.500 mol of each of the following solutes is dissolved in 2.0 L of water, which will cause the greatest increase in the boil

serious [3.7K]

Answer is: D. Na2SO4.

b(solution) = 0.500 mol ÷ 2.0 L.

b(solution) = 0.250 mol/L.

b(solution) = 0.250 m; molality of the solutions.

ΔT = Kf · b(solution) · i.

Kf - the freezing point depression constant.

i - Van 't Hoff factor.

Dissociation of sodium sulfate in water: Na₂SO₄(aq) → 2Na⁺(aq) + SO₄²⁻(aq).

Sodium sulfate dissociates on sodium cations and sulfate anion, sodium sulfate has approximately i = 3.

Sodium chloride (NaCl) and potassium iodide (KI) have Van 't Hoff factor approximately i = 2.

Carbon dioxide (CO₂) has covalent bonds (i = 1, do not dissociate on ions).

Because molality and the freezing point depression constant are constant, greatest freezing point lowering is solution with highest Van 't Hoff factor.

8 0

3 years ago

Read 2 more answers

What is the color of the flame when magnesium burns in air ​

What is the color of the flame when magnesium burns in air