What are two objects used to find density

2. How much heat is released when 432g of water cools down from 710C to 180C?

nadya68 [22]

The heat released by the water when it cools down by a temperature difference AT

is Q = mC,AT

where

m=432 g is the mass of the water

C, = 4.18J/gºC

is the specific heat capacity of water

AT = 71°C -18°C = 530

is the decrease of temperature of the water

Plugging the numbers into the equation, we find

Q = (4329)(4.18J/9°C)(53°C) = 9.57. 104J

and this is the amount of heat released by the water.

7 0

3 years ago

What size volumetric flask would you use to create a 1.00M solution using 166.00 g of KI?

mr Goodwill [35]

Answer:

A 1 liter volumetric flask should be used.

Explanation:

First we convert 166.00 g of KI into moles, using its molar mass:

Molar mass of KI = Molar mass of K + Molar mass of I = 166 g/mol

166.00 g ÷ 166 g/mol = 1 mol KI

Then we calculate the required volume, using the definition of molarity:

Molarity = moles / liters

Liters = moles / molarity

1 mol / 1.00 M = 1 L

3 0

2 years ago

The burning of a sample of propane

r-ruslan [8.4K]

Answer:

70.0°C

Explanation:

We are given;

Amount of heat generated by propane as 104.6 kJ or 104600 Joules
Mass of water is 500 g
Initial temperature as 20.0 ° C

We are required to determine the final temperature of water;

Taking the initial temperature is x°C

We know that the specific heat of water is 4.18 J/g°C

Quantity of heat = Mass × specific heat × change in temperature

In this case;

Change in temp =(x-20)° C

Therefore;

104600 J = 500 g × 4.18 J/g°C × (x-20)

104600 J = 2090x -41800

146400 = 2090 x

x = 70.0479

=70.0 °C

Thus, the final temperature of water is 70.0°C

7 0

3 years ago

A gas used to extinguish fires is composed of 75 % CO2 and 25 % N2. It is stored in a 5 m3 tank at 300 kPa and 25 °C. What is th

tatyana61 [14]

Answer : The partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

Explanation :

As we are given 75 % $CO_2$ and 25 % $N_2$ in terms of volume.

First we have to calculate the moles of $CO_2$ and $N_2$ .

$\text{Moles of }CO_2=\frac{\text{Volume of }CO_2}{\text{Volume at STP}}=\frac{75}{22.4}=3.35mole$

$\text{Moles of }N_2=\frac{\text{Volume of }N_2}{\text{Volume at STP}}=\frac{25}{22.4}=1.12mole$

Now we have to calculate the mole fraction of $CO_2$ .

$\text{Mole fraction of }CO_2=\frac{\text{Moles of }CO_2}{\text{Moles of }CO_2+\text{Moles of }N_2}$

$\text{Mole fraction of }CO_2=\frac{3.35}{3.35+1.12}=0.75$

Now we have to calculate the partial pressure of the $CO_2$ gas.

$\text{Partial pressure of }CO_2=\text{Mole fraction of }CO_2\times \text{Total pressure of gas}$

$\text{Partial pressure of }CO_2=0.75mole\times 300Kpa=225Kpa=225Kpa\times \frac{0.145\text{ psia}}{1Kpa}=32.625\text{ psia}$

conversion used : (1 Kpa = 0.145 psia)

Therefore, the partial pressure of the $CO_2$ in the tank in psia is, 32.6 psia.

3 0

2 years ago

What is the net ionic equation for the reaction ofFeCl3 and KOH in water?

Levart [38]

Answer:

Fe³⁺(aq) + 3 OH⁻(aq) → Fe(OH)₃(s)

Explanation:

First, we will write the molecular equation because it is the easiest to balance.

FeCl₃(aq) + 3 KOH(aq) → Fe(OH)₃(s) + 3 KCl(aq)

The full ionic equation includes all the ions and the molecular species.

Fe³⁺(aq) + 3 Cl⁻(aq) + 3 K⁺(aq) + 3 OH⁻(aq) → Fe(OH)₃(s) + 3 K⁺(aq) + 3 Cl⁻(aq)

The net ionic equation includes only the ions that participate in the reaction and the molecular species.

Fe³⁺(aq) + 3 OH⁻(aq) → Fe(OH)₃(s)

8 0

3 years ago