Write the full ground-state electron configuration for each element. (a) s:

If 45.0 mL of ethanol (density = 0.789 g/mL) initially at 8.0 ∘C is mixed with 45.0 mL of water (density = 1.0 g/mL) initially a

strojnjashka [21]

Answer : The final temperature of the mixture is, $22.14^oC$

Explanation :

First we have to calculate the mass of ethanol and water.

$\text{Mass of ethanol}=\text{Density of ethanol}\times \text{Volume of ethanol}=0.789g/mL\times 45.0mL=35.5g$

and,

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1.0g/mL\times 45.0mL=45.0g$

Now we have to calculate the final temperature of the mixture.

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

$q_1=-q_2$

$m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)$

where,

$c_1$ = specific heat of ethanol = $2.42J/g^oC$

$c_2$ = specific heat of water = $4.18J/g^oC$

$m_1$ = mass of ethanol = 35.5 g

$m_2$ = mass of water = 45.0 g

$T_f$ = final temperature of mixture = ?

$T_1$ = initial temperature of ethanol = $8.0^oC$

$T_2$ = initial temperature of water = $28.6^oC$

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

$35.5g\times 2.42J/g^oC\times (T_f-8.0)^oC=-45.0g\times 4.18J/g^oC\times (T_f-28.6)^oC$

$T_f=22.14^oC$

Therefore, the final temperature of the mixture is, $22.14^oC$

3 0

3 years ago

Define Condensation .

ozzi

Answer:

Condensation is the change of the physical state of matter from the gas phase into the liquid phase.

6 0

2 years ago

Read 2 more answers

Suppose the half-life is 9.0 s for a first order reaction and the reactant concentration is 0.0741 M 50.7 s after the reaction s

bazaltina [42]

<u>Answer:</u> The time taken by the reaction is 84.5 seconds

<u>Explanation:</u>

The equation used to calculate half life for first order kinetics:

$k=\frac{0.693}{t_{1/2}}$

where,

$t_{1/2}$ = half-life of the reaction = 9.0 s

k = rate constant = ?

Putting values in above equation, we get:

$k=\frac{0.693}{9}=0.077s^{-1}$

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$ ......(1)

where,

k = rate constant = $0.077s^{-1}$

t = time taken for decay process = 50.7 sec

$[A_o]$ = initial amount of the reactant = ?

[A] = amount left after decay process = 0.0741 M

Putting values in equation 1, we get:

$0.077=\frac{2.303}{50.7}\log\frac{[A_o]}{0.0741}$

$[A_o]=3.67M$

Now, calculating the time taken by using equation 1:

$[A]=0.0055M$

$k=0.077s^{-1}$

$[A_o]=3.67M$

Putting values in equation 1, we get:

$0.077=\frac{2.303}{t}\log\frac{3.67}{0.0055}\\\\t=84.5s$

Hence, the time taken by the reaction is 84.5 seconds

6 0

3 years ago

PLEASE HELP ME ASAP What is the volume of 28.9 g of mercury if the density is 13.8 g/mL? *

strojnjashka [21]

Answer:

2.09 mL

Explanation:

density = mass/volume

13.8 = 28.9/v

13.8v = 28.9

v = 2.09 mL

8 0

3 years ago

a scuba diver's tank contains 0.29g of oxygen compressed into volume of 2.3L. What is the pressure in the tank at 9C?

viva [34]

Answer:

The answer to your question is P = 0.18 atm

Explanation:

Data

mass of O₂ = 0.29 g

Volume = 2.3 l

Pressure = ?

Temperature = 9°C

constant of ideal gases = 0.082 atm l/mol°K

Process

1.- Convert the mass of O₂ to moles

16 g of O₂ -------------------- 1 mol

0.29 g of O₂ ---------------- x

x = (0.29 x 1)/16

x = 0.29/16

x = 0.018 moles

2.- Convert the temperature to °K

Temperature = 9 + 273 = 282°K

3.- Use the ideal gas law ro find the answer

PV = nRT

-Solve for P

P = nRT/V

-Substitution

P = (0.018 x 0.082 x 282) / 2.3

-Simplification

P = 0.416/2.3

-Result

P = 0.18 atm

5 0

3 years ago