Aluminum can react with oxygen gas to produce aluminum oxide (Al¿OÀ). What type of reaction is this?

How much energy is required to convert 15.0 g of ice at −106 °C to water vapor at 125 °C? Specific heats are 2.09 J/g K for both

myrzilka [38]

Answer:

49.3 kJ of energy is required

Explanation:

An exercise of calorimetry at its best

First of all, convert the ice to water before melting.

Q = ice mass . C . ΔT

Q = 15 g . 2.09 J/g°C (0° - (-106°C)

15 g . 2.09 J/g°C . 106°C = 3323.1 J

Now we have to melt the ice, to change its state

Q = mass . latent heat of fusion

Q = 15 g . 0.335 kJ/g = 5.025 kJ .1000 = 5025 J

After that, we have liquid water at 0° and the ice has melted completely. We have to release energy to make a temperature change, to 100° (vaporization)

Q = 15g . 4.18 J/g°C (100°C - 0°C)

Q = 6270 J

Water has been vaporizated so we have to calculate, the state change.

Q = mass . latent heat of vap

Q = 15 g. 2.260 kJ/g

Q = 33.9 kJ (.1000) = 33900 J

Finally we have to increase temperature from 100°C to 125°C

Q = 15 g . 2.09 J/g°C . (125°C - 100°C)

Q = 783.75 J

To know how much energy is required to conver 15 g of ice, to water vapor at 125°C, just sum all the heat released.

3323.1 J + 5025 J + 6270 J + 33900 J + 783.75 J = 49301.85 joules.

Notice I have to convert kJ to J in two calcules to make the sum.

49301.85 joules / 1000 = 49.3 kJ

4 0

2 years ago

Which of the following words/phrases correctly describe(s) sugar water? Select all that apply.

Paul [167]

Answer:

Heterogeneous mixture solution

Explanation:

The reason this is Heterogeneous is that you cant see each individual compound in the solution. If this was sand or any compund that is not desolvable or not fully desolved in water would be Homogenous since you can see the individual compounds (water and sand)

6 0

3 years ago

What are the magnitude (size) and direction of the cumulative force acting on the car shown in the picture A. 30 N to the right

UNO [17]

Answer: The correct answer is option(A).

Explanation:

Total forces exerting on the car = F

$F_r=50 N$ = Force on car exerting in right direction

$F_l=20 N$ = Force on car exerting in left direction

$F_u=2500 N$ = Force on car exerting in upward direction

$F_d=2500 N$ = Force on car exerting in downward direction

$F=F_r+F_l+F_u+F_d$

$(-F_u)=F_d$ (negative sign shows the direction)

Since, upward force are equal in magnitude but opposite in direction by which they will balance out each other.so, the net force car will be due to two forces $F_r$ and $F_l$

$F=F_r+F_l=50 N+(-20 N)=30 N$ (negative shows the direction)

The magnitude (size) and direction of the cumulative force acting on the car will 30 N towards right direction.Hence, correct answer is option(A).

4 0

3 years ago

Read 2 more answers

Destruction of mountains can lead to what

Zina [86]

Answer:

liquid magma

Explanation:

6 0

3 years ago

Which of these substances acts as a buffer? a. blood b. lemon juice c. curd

il63 [147K]

The correct answer is( A) blood.

when the buffer solution its PH value changes very little when a small amount

of strong acid or base is added to it, and here the bicarbonate buffering system is used to regular the PH of the blood that keeping the PH at nearly constant value by maintaining the original acidity or basicity of the solution.

7 0

3 years ago