All categories

3 years ago

What is the condition of the outside air at a certain time and place?

Chemistry

2 answers:

11111nata11111 [884]3 years ago

6 0

Weather... weather is the obvious answer

olga2289 [7]3 years ago

4 0

Weather or climate is another possible answer.

You might be interested in

Cyclopropene decomposes to propene when heated to 500 C, calculate rate constant for the first order reaction 0 min 1.48 mmol/L

Dmitry_Shevchenko [17]

Answer:

k = 0.0306 min-1

Explanation:

The table is given as;

Time, Concentration

0 1.48

5 1.27

10 0.98

15 0.84

The integrated rate law for a first order reaction is given as;

ln [A] = -kt + ln [Ao]

where;

[A] = Final Concentration

[Ao] = Initial Concentration

k = rate constant

t = time

In the table, taking the first two sets of values;

t = 5

k = ?

[Ao] = 1.48

[A] = 1.27

Inserting into the equation;

ln(1.27) = - k (5) + ln(1.48)

ln(1.27) - ln(1.48) = -5k

-0.1530 = -5k

k = -0.1530 / -5

k = 0.0306 min-1

6 0

3 years ago

NH4NO3, whose heat of solution is 25.7 kJ/mol, is one substance that can be used in cold pack. If the goal is to decrease the te

makvit [3.9K]

Answer:

There are necessaries 35,2g of NH₄NO₃ per 100,0g of water to decrease the temperature of the solution from 25,0°C to 5,0°C

Explanation:

To decrease the temperature of the solution there are necessaries:

4,184J/g°C×(5,0°C-25,0°C)×(100,0g+X) = -Y

8368J + 83,68J/gX = Y (1)

Where x are grams of NH₄NO₃ you need to add and Y is the energy that you need to decrease the heat.

Also, the energy Y will be:

Y = 25700J/mol× $\frac{1mol}{80,043g}$ X

Y = 321J/g X (2)

Replacing (2) in (1)

8368J + 83,68J/g X = 321J/g X

8363J = 237,32J/gX

X = 35,2g

Thus, there are necessaries 35,2g of NH₄NO₃ per 100,0g of water to decrease the temperature of the solution from 25,0°C to 5,0°C

I hope it helps!

6 0

3 years ago

1. Which of the following is a correctly written thermochemical equation?

WITCHER [35]

Explanation:

1. Thermochemical equation is balance stoichiometric chemical equation written with the phases of the reactants and products in the brackets along with the enthalpy change of the reaction.

The given correct thermochemical reactions are:

$Fe(s)+O_2(g)\rightarrow Fe_2O_3(s),\Delta H = 3,926 kJ
$

$C_3H_8(g)+5O_2 (g)\rightarrow 3CO_2 (g)+4H_2O(l),\Delta H= 2,220 kJ/mol$

2. Phase change affect the value of the enthalpy change of the thermochemical equation. This is because change in phase is accompanied by change in energy. For example:

$H_2O(s)\rightarrow H_2O(g),\Delta H_{s}=51.1 kJ/mol$