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3 years ago

Class 9 Chapter: Structure of the Atom What are the alpha particles compared to?Why?

1 answer:

7 0

Alpha particles are highly ionising because of their double positive charge, large mass (compared to a beta particle) and because they are relatively slow. They can cause multiple ionisations within a very small distance.

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How many moles of solute are contained in a 500.0 milliliter solution that has a concentration of 0.35 M?

RUDIKE [14]

I think the answer you are looking for is .18 moles

8 0

4 years ago

Read 2 more answers

A sample of gas is kept at a temperature of 300 k, a volume of 1.45L, and a pressure of 3.00 kPa. How many moles of has are in t

klasskru [66]

Answer:

the number of moles of the gas is 0.00174 mol.

Explanation:

Given;

temperature of the, T = 300 K

volume of the gas, V = 1.45 L

Pressure of the gas, P = 3.0 kPa

The number of moles of the gas is calculated using Ideal gas equation, as follows;

PV = nRT

Where;

n is number of moles of the gas

R is the ideal gas constant, = 8.315 L.kPa/mol.K

n = PV / RT

n = (3 x 1.45) / (8.315 x 300)

n = 0.00174 mol.

Therefore, the number of moles of the gas is 0.00174 mol.

7 0

3 years ago

During prophase a group of fibers called what forms the cell

11Alexandr11 [23.1K]

Answer:

During prophase, the nucleus disappears, spindle fibers form, and DNA condenses into chromosomes ( sister chromatids ). During metaphase, the sister chromatids align along the equator of the cell by attaching their centromeres to the spindle fibers.

Explanation:

4 0

3 years ago

Read 2 more answers

15.50 g of NH4Cl reacts with an excess of AgNO3. In the reaction 35.50 g AgCl is produced. what is the theoretical yield of AgCl

Shkiper50 [21]

Answer:

41.56 g

Explanation:

Given data:

Mass of NH₄Cl = 15.50 g

Actual yield of AgCl = 35.50 g

Theoretical yield of AgCl = ?

Solution:

Chemical equation:

NH₄Cl + AgNO₃ → AgCl + NH₄NO₃

Number of moles of NH₄Cl:

Number of moles = mass/ molar mass

Number of moles = 15.50 g/ 53.491 g/mol

Number of moles = 0.29 mol

Now we will compare the moles of NH₄Cl with AgCl .

NH₄Cl : AgCl

1 : 1

0.29 : 0.29

Theoretical yield of AgCl:

Mass = number of moles × molar mass

Mass = 0.29 mol ×143.32 g/mol

Mass = 41.56 g

4 0

3 years ago

What temperature will the water reach when 10.1 g CaO is dropped into a coffee cup containing 157 g H2O at 18.0°C if the followi

Zepler [3.9K]

Answer:

Final temperature attained by water = 34.6°C

Explanation:

The reaction of CaO and H₂O is an <em>exothermic reaction</em>. The equation of reaction is given below:

CaO + H₂O ----> Ca(OH)₂

The quantity of heat given off, ΔH°rxn = 64.8KJ/mol = 64800J/mol

Number of moles of CaO = mass/molar mass, where molar mass of Ca0 = 56g/mol, mass of CaO = 10.1g

Number of moles of CaO = 10.1g/56g/mol =0.179moles

Quantity of heat given off by 0.179 moles = 64800 *0.179 = 11599.2J/mol

Using the formula, <em>Quantity of heat, q = mass * specific heat capacity * temperature rise.</em>

mass of mixture = (10.1 + 157)g = 167.1g, Initial temperature = 18.0°C

Final temperature(T₂) - Initial temperature(T₁) = Temperature rise

11599.2J/mol = 167.1g * 4.18J/g·°C * ( T₂ - 18.0°C)

11599.2 = 698.478T₂ - 12572.604

11599.2 + 12572.604 = 698.478T₂

698.478T₂ = 24171.804

T₂ = 34.6°C

Therefore, final temperature attained by water = 34.6°C

6 0

4 years ago