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4 years ago

Which elements are most metallic? Li, Be, B, C

1 answer:

4 0

Firstly, carbon isn't a metal.

Boron is a metalloid.

Beryllium is the least metallic alkaline earth metal, and lithium is the least metallic alkaline metal.

Both are metallic, and have metallic appearances and conduct electricity, but beryllium is more brittle than lithium.

So, I'd say Li and Be are equal.

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g A high altitude balloon is filled with 1.41 x 104 L of hydrogen gas (H2) at a temperature of 21oC and a pressure of 745 torr.

Tamiku [17]

Answer:

1.27 × 10⁵ L

Explanation:

Step 1: Given data

Initial pressure (P₁): 745 Torr

Initial volume (V₁): 1.41 × 10⁴ L

Inital temperature (T₁): 21 °C

Final pressure (P₂): 63.1 Torr

Final volume (V₂): ?

Final temperature (T₂): -48 °C

Step 2: Convert the temperatures to the Kelvin scale

We will use the following expression.

K = °C + 273.15

K = 21 °C + 273.15 = 294 K

K = -48 °C + 273.15 = 225 K

Step 3: Calculate the final volume of the balloon

We will use the combined gas law.

P₁ × V₁ / T₁ = P₂ × V₂ / T₂

V₂ = P₁ × V₁ × T₂/ T₁ × P₂

V₂ = 745 Torr × 1.41 × 10⁴ L × 225 K/ 294 K × 63.1 Torr

V₂ = 1.27 × 10⁵ L

6 0

3 years ago

Two solid samples each contain sulfur, oxygen, and sodium, only. These samples have the same color, melting point, density, and

katovenus [111]

The correct answer is 1. compound. There are three elements and not just one so it's not element. Mixtures wouldn't have the same properties that you described but these do so it's a compounds. Solution is not a solid thing but rather a liquid one. The two samples are therefore compounds.

7 0

3 years ago

On a summer day early in the moming, a balloon is filled with helium when the temperature

MAXImum [283]

Based on the data provided;

number of moles of helium gas is 1.25 moles
pressure at peak temperature is 259.3 kPa
internal pressure is above 256 kPa, therefore, the balloon will burst.
pressure should be reduced to a value less than 256 kPa by reducing the temperature

<h3>What is the ideal has equation?</h3>

The ideal gas equation relatesthe pressure, volume, moles and temperature of a gas.

The moles of helium gas is calculated using the Ideal gas equation:

PV = nRT

n is the number of moles of gas

R is molar gas constant = 8.314 L⋅kPa/Kmol

P is pressure = 239 kPa

T is temperature = 21°C = 294 K

V is volume = 12.8 L

Therefore;

n = PV/RT

n = 239 × 12.8 / 8.314 × 294

n = 1.25 moles

The number of moles of helium gas is 1.25 moles

At peak temperature, T = 46°C = 319 K

Using P1/T1 = P2/T2

P2 = P1T2/T1

P2 = 239 × 319/294

P2 = 259.3 kPa

The pressure at peak temperature is 259.3 kPa

At 42°C, T = 315 K

Using P1/T1 = P2/T2

P2 = P1T2/T1

P2 = 239 × 315/294

P2 = 256.07 kPa

Since the internal pressure is above 256 kPa, the balloon will burst.

The pressure should be reduced to a value less than 256 kPa by reducing the temperature.

Learn more about gas ideal gas equation at: brainly.com/question/12873752

6 0

2 years ago

Which types of reactions would result in the formation of precipitate?

IRINA_888 [86]

Answer:

Double Displacement Reaction

Explanation:

A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.

8 0

3 years ago

How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction SiO2(g) + 3C(s) → Si

defon

Answer:

31.24 kJ

Explanation:

SiO₂(g) + 3C(s) → SiC(s) + 2CO(g) ΔH° = 624.7 kJ/mol

First we convert 3.00 grams of SiO₂ to moles, using its molar mass:

3.00 g SiO₂ ÷ 60.08 g/mol = 0.05 mol

Now we calculate the heat absorbed, using the given ΔH°:

If the complete reaction of 1 mol of SiO₂ absorbs 624.7 kJ, then with 0.05 mol:

0.05 mol * 624.7 kJ/mol = 31.24 kJ of heat would be absorbed.

6 0

3 years ago