In general, the greatest variation happens in populations of organisms that reproduce____

When you combine 50.0 mL of 0.100 M AgNO3 with 50.0 mL of 0.100 M HCl in a coffee-cup calorimeter, the temperature changes from

RideAnS [48]

Answer : The enthalpy of reaction $(\Delta H_{rxn})$ is, 67.716 KJ/mole

Explanation :

First we have to calculate the moles of $AgNO_3$ and $HCl$ .

$\text{Moles of }AgNO_3=\text{Molarity of }AgNO_3\times \text{Volume}=(0.100mole/L)\times (0.05L)=0.005mole$

$\text{Moles of }HCl=\text{Molarity of }HCl\times \text{Volume}=(0.100mole/L)\times (0.05L)=0.005mole$

Now we have to calculate the moles of AgCl formed.

The balanced chemical reaction will be,

$AgNO_3(aq)+HCl(aq)\rightarrow AgCl(s)+HNO_3(aq)$

As, 1 mole of $AgNO_3$ react with 1 mole of $HCl$ to give 1 mole of $AgCl$

So, 0.005 mole of $AgNO_3$ react with 0.005 mole of $HCl$ to give 1 mole of $AgCl$

The moles of AgCl formed = 0.005 mole

Total volume of the solution = 50.0 ml + 50.0 ml = 100.0 ml

Now we have to calculate the mass of solution.

Mass of the solution = Density of the solution × Volume of the solution

Mass of the solution = 1.00 g/ml × 100.0 ml = 100 g

Now we have to calculate the heat.

$q=m\times C\Delta T=m\times C \times (T_2-T_1)$

where,

q = heat

C = specific heat capacity = $4.18J/g^oC$

m = mass = 100 g

$T_2$ = final temperature = $24.21^oC$

$T_1$ = initial temperature = $23.40^oC$

Now put all the given values in the above expression, we get:

$q=100g\times (4.18J/g^oC)\times (24.21-23.40)^oC$

$q=338.58J$

Now we have to calculate the enthalpy of the reaction.

$\Delta H_{rxn}=\frac{q}{n}$

where,

$\Delta H_{rxn}$ = enthalpy of reaction = ?

q = heat of reaction = 338.58 J

n = moles of reaction = 0.005 mole

Now put all the given values in above expression, we get:

$\Delta H_{rxn}=\frac{338.58J}{0.005mole}=6771.6J/mole=67.716KJ/mole$

Conversion used : (1 KJ = 1000 J)

Therefore, the enthalpy of reaction $(\Delta H_{rxn})$ is, 67.716 KJ/mole

4 0

3 years ago

A sample of an unknown gas occupies 5.51 L at 1.31 atm. What pressure would thisgas exert in a 0.520 L container if the temperat

weeeeeb [17]

Answer:

P₂ = 13.9 atm (3 sig. figs.)

Explanation:

The pressure (P), Volume (V) relationship with Temperature (T) & mass (n) held constant is an inverse proportionality. That is Boyles Law ...

P ∝ 1/V => P = k/V => k = P·V

For two pressure-volume conditions, the proportionality constant (k) remains constant where k₁ = k₂ and P₁·V₁ = P₂·V₂ => P₂ = P₁·V₁/V₂

Given:

P₁ = 1.31 atm.

V₁ = 5.51 L

P₂ = ?

V₂ = 0.520 L

V₂ = (1.31 atm)(5.51L)/(0.520L) = 13.88096154 atm (calc. ans.) = 13.9 atm (3 sig. figs.)

5 0

3 years ago

How many atoms are in 3.20 moles of carbon

DIA [1.3K]

Answer:

19.264× $10^{23}$ atoms are present in 3.2 moles of carbon.

Explanation:

It is known that one mole of each element is composed of Avagadro's number of atoms. This is same for all the elements in the periodic table.

So, as 1 mole of any element = Avagadro's number of atoms = 6.02× $10^{23}$ atoms

It is as simple as understanding a dozen of anything is equal to 12 pieces of that object.

As here the moles of carbon is given as 3.20 moles, the number of atoms in this mole can be determined as below.

1 mole of carbon = 6.02 × $10^{23}$ atoms

Then, 3.20 moles of carbon = 3.20 × 6.02 × $10^{23}$ atoms

Thus, 19.264× $10^{23}$ atoms are present in 3.2 moles of carbon.

6 0

3 years ago

Which of the following is the correct formula for sodium oxide? NaO2 NaO Na2O3 Na3O4 Na2O

olga nikolaevna [1]

Since Na has a 1+ charge and O has a -2 charge, by reversing the charges and placing them as subscripts for the other atoms the formula is Na2O1 or simply Na2O.

7 0

3 years ago

A worker at a nuclear power plant has noticed that his dosimeter alarm has

Sphinxa [80]

Answer:

Radiation is being released from the reactor.

Explanation:

( A P E X )

5 0

3 years ago

In general, the greatest variation happens in populations of organisms that reproduce_____.