Which ions have ten electrons in the outermost subshell?

A 0.630 gram sample of a metal, M, reacts completely with sulfuric acid according to:A volume of 291 mL of hydrogen is collected

Lina20 [59]

Answer:

55.0 g/mol

Step-by-step explanation:

Step 1. Partial pressure of hydrogen

You are collecting the gas over water, so

$p_{\text{atm}} = p_{\text{H}_{2}} + p_{\text{H}_{2}\text{O}}$

$p_{\text{H}_{2}} = p_{\text{atm}} - p_{\text{H}_{2}\text{O}}$

$p_{\text{atm}} = \text{756.0 Torr}$

At 25 °C, $p_{\text{H}_{2}\text{O}} = \text{23.8 Torr}$

$p_{\text{H}_{2}} = \text{756.0 Torr} - \text{23.8 Torr} = \text{732.2 Torr}$

===============

Step 2. Moles of H₂

We can use the Ideal Gas Law.

pV = nRT Divide both sides by RT

n = (pV)/(RT)

p = 732.2 Torr Convert to atmospheres

p = 732.2/760

p = 0.9634 atm

V = 291 mL Convert to litres

V = 0.291 L

R = 0.082 06 L·atm·K⁻¹mol⁻¹

T = 25 °C Convert to kelvins

T = (25 + 273.15 ) K = 298.15 K

n = (0.9632 × 0.291)/(0.082 06 × 298.15)

n = 0.2804/24.47

n = 0.011 46 mol

===============

Step 3. Moles of metal

The partial chemical equation is

M + H₂SO₄ ⟶ H₂ + …

The molar ratio of M:H₂ is 1 mol M:1 mol H₂.

Moles of M = 0.011 46× 1/1

Moles of M = 0.011 46 mol M

===============

Step 4. Atomic mass of M

Atomic mass = mass of M/moles of M

Atomic mass = 0.630/0.011 46

Atomic mass = 55.0 g/mol

7 0

4 years ago

Heating of glass until it melts what change is it

Natasha2012 [34]

Answer:

physcial change

Explanation:

As it has visible changes on shape and size

4 0

2 years ago

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Define ionization energy and explain why the second aisle and ionization energy of the element is higher than its ionization ene

seraphim [82]

Define ionization energy and explain why the second aisle and ionization energy of the element is higher than its ionization energy

The energy needed to remove one or more electrons from a neutral atom to form a positively charged ion is a physical property that influences the chemical behavior of the atom. By definition, the first ionization energy of an element is the energy needed to remove the outermost, or highest energy, electron from a neutral atom in the gas phase.

The process by which the first ionization energy of hydrogen is measured would be represented by the following equation.

H(g) -----> H+(g) + e- deltaHo = -1312.0 kJ/mol

6 0

3 years ago

A vial of amoxicillin contains 500 mg in 2.0 mL of solution. What volume of the solution contains 180 mg of the drug

Tom [10]

0.72 mL of solution will have 180 mg of amoxicillin. For this problem, you need to calculate the equivalent ratio of volume as to the ratio of amoxicillin. So 180/500 = X/2.0 Multiply both sides by 2 2 * 180/500 = X 360/500 = X 18/25 = X 0.72 = X So you need 0.72 mL of solution to get 180 mg of the drug.

3 0

3 years ago

If it takes 7,529 calories of heat to warm 750.0 grams of water, what was the temperature change? The specific heat of water in

Zigmanuir [339]

Answer:

The temperature change was 10.04 °C.

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system. In this way, there is a direct proportional relationship between heat and temperature. The constant of proportionality depends on the substance that constitutes the body as on its mass, and is the product of the specific heat by the mass of the body. So, the equation that allows calculating heat exchanges is:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case you know:

Q= 7,529 calories (cal)

c= 1 $\frac{cal}{g*C}$

M=750 grams

Replacing:

7,529 cal= 1 $\frac{cal}{g*C}$ *750 g* ΔT

Solving you get:

ΔT= $\frac{7,529 cal}{1 \frac{cal}{g*C}*750 g }$

ΔT= 10.04 °C

So, the temperature change was 10.04 °C.

6 0

3 years ago

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