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2 years ago

How many grams are contained in a 0.893 mol sample of methane, ch4?

1 answer:

6 0

We are given with a compound, Methane (CH4), with a molar mass of 0.893 mol sample. We are tasked to solve for it's corresponding mass in g. We need to solve first the molecular weight of Methane, that is

C=12 g/mol

H=1g/mol

CH4= 12 g/mol +1(4) g/mol = 16 g/mol

With 0.893 mol sample, its corresponding mass is

g CH4= 0.893 mol x 16g/mol =14.288 g

Therefore, the mass of methane is 14.288 g

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Calculate the amount of heat necessary to raise the temperature of 135.0 g of water from 50.4°F to 85.0°F. The specific heat of

MAXImum [283]

Here we have to calculate the heat required to raise the temperature of water from 85.0 ⁰F to 50.4 ⁰F.

10.857 kJ heat will be needed to raise the temperature from 50.4 ⁰F to 85.0 ⁰F

The amount of heat required to raise the temperature can be obtained from the equation H = m×s×(t₂-t₁).

Where H = Heat, s =specific gravity = 4.184 J/g.⁰C, m = mass = 135.0 g, t₁ (initial temperature) = 50.4 ⁰F or 10.222 ⁰C and t₂ (final temperature) = 85.0⁰F or 29.444 ⁰C.

On plugging the values we get:

H = 135.0 g × 4.184 J/g.⁰C×(29.444 - 10.222) ⁰C

Or, H = 10857.354 J or 10.857 kJ.

Thus 10857.354 J or 10.857 kJ heat will be needed to raise the temperature.

6 0

2 years ago

A 25 gram(m) metal ball is heated to 200C(delta T) with 2330 Joules(q) of energy. What is the specific heat of the metal?

Dominik [7]

Answer:

The specific heat of the metal is 0.466 $\frac{J}{g*C}$

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

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:

Q= 2330 J
c= ?
m= 25 g
ΔT= 200 °C

Replacing:

2330 J= c*25 g* 200 °C

Solving:

$c=\frac{2330 J}{25 g* 200 C}$

c=0.466 $\frac{J}{g*C}$

The specific heat of the metal is 0.466 $\frac{J}{g*C}$

6 0

2 years ago

Read 2 more answers

If a concentration of 10 fluorescent molecules per μm2of cell membrane is needed to visualize a cell under the microscope, how m

lara [203]

Answer : Total molecules that will be needed to visualize a single egg will be 78500 molecules of dye.

Explanation : As a single egg cell has an approximately diameter of 100 μm.

We can use this formula to calculate area of the cell membrane;

A = π $(100)^{2} / 4$ ;

We can take π as 3.14 and we get;

A = 3.14 X $(100)^{2} / 4$

Soving we get;

A = 7850 μ $m^{2}$

Here we have to calculate the amount of dye molecules which will be needed for 10 fluorescent molecules / μ $m^{2}$ but;

here 1 μ $m^{2}$ = 7850 μ $m^{2}$ dye molecules.

Therefore, 10 fluorescent molecules will need;

7850 X 10 = 78500 molecules of dye.

Therefore, the answer is 78500 molecules of dye.

6 0

2 years ago

Explain why groups 14 and 15 are better representatives of mixed groups than groups 13 and 16

Brrunno [24]

<h3>Answer;</h3>

Groups 14 and 15 each contain metals, nonmetals, and metalloids while Group 13 contains metals and a metalloid, and Group 16 contains metalloids and nonmetals.

<h3>Explanation;</h3>

Groups 13–16 of the periodic table contain one or more metalloids, in addition to metals, nonmetals, or both.
Unlike other groups of the periodic table, which contain elements in one class, groups 13–16 referred to as mixed groups contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both.
Group 14 also known as the carbon group contains carbon which is a non metal, silicon and germanium which are metalloids and tin and lead which are metals.
Group 15 also known as the Nitrogen group contains non metals such as oxygen, metalloid tellurium and a metal polonium.

3 0

2 years ago

The activation energy for the reaction NO2(g)+CO(g)⟶NO(g)+CO2(g) is Ea = 375 kJ/mol and the change in enthalpy for the reaction

HACTEHA [7]

Answer: 625 kj/mol

Explanation:

As shown below this expression gives the activation energy of the reverse reaction:

EA reverse reaction = EA forward reaction + | enthalpy change |

1) The activation energy, EA is the difference between the potential energies of the reactants and the transition state:

EA = energy of the transition state - energy of the reactants.

2) The activation energy of the forward reaction given is:

EA = energy of the transition state - energy of [ NO2(g) + CO(g) ] = 75 kj/mol

3) The negative enthalpy change - 250 kj / mol for the forward reaction means that the products are below in the potential energy diagram, and that the potential energy of the products, [NO(g) + CO2(g) ] is equal to 375 kj / mol - 250 kj / mol = 125 kj/mol

4) For the reverse reaction the reactants are [NO(g) + CO2(g)], and the transition state is the same than that for the forward reaction.

5) The difference of energy between the transition state and the potential energy of [NO(g) + CO2(g) ] will be the absolute value of the change of enthalpy plus the activation energy for the forward reaction:

EA reverse reaction = EA forward reaction + | enthalpy change |

EA reverse reaction = 375 kj / mol + |-250 kj/mol | = 375 kj/mol + 250 kj/mol = 625 kj/mol.

And that is the answer, 625 kj/mol

4 0

2 years ago