Which element has the greatest average atomic mass?

What expression approximates the volume of O2 consumed, measure at STP, when 55 g of Al reacts completely with excess O2?2 Al(s)

nikdorinn [45]

Answer : The volume of $O_2$ consumed are, $0.75\times 2\times 22.4$ L.

Explanation :

The balanced chemical reaction will be:

$4Al(s)+3O_2(g)\rightarrow 2Al_2O_3(s)$

First we have to calculate the moles of Al.

$\text{Moles of }Al=\frac{\text{Mass of }Al}{\text{Molar mass of }Al}$

Molar mass of Al = 27 g/mole

$\text{Moles of }Al=\frac{55g}{27g/mol}=2mole$

Now we have to calculate the moles of $O_2$ .

From the reaction we conclude that,

As, 4 mole of Al react with 3 moles of $O_2$

So, 2 mole of Al react with $\frac{3}{4}\times 2=0.75\times 2$ moles of $O_2$

Now we have to calculate the volume of $O_2$ consumed.

As we know that, 1 mole of substance occupies 22.4 liter volume of gas.

As, 1 mole of $O_2$ occupies 22.4 liter volume of $O_2$ gas

So, $0.75\times 2$ mole of $O_2$ occupies $0.75\times 2\times 22.4$ liter volume of $O_2$ gas

Therefore, the volume of $O_2$ consumed are, $0.75\times 2\times 22.4$ L.

3 0

3 years ago

HELP!! Suppose that the pressure of 1.00 L of gas is 380 mm Hg when the temperature is 200. K. At what

Korolek [52]

Numa máquina térmica uma parte da energia térmica fornecida ao sistema(Q1) é transformada em trabalho mecânico (τ) e o restante (Q2) é dissipado, perdido para o ambiente.

sendo:

τ: trabalho realizado (J) [Joule]
Q1: energia fornecida (J)
Q2: energia dissipada (J)

temos: τ = Q1 - Q2

O rendimento (η) é a razão do trabalho realizado pela energia fornecida:

η= τ/Q1

Exercícior resolvido:
Uma máquina térmica cíclica recebe 5000 J de calor de uma fonte quente e realiza trabalho de 3500 J. Calcule o rendimento dessa máquina térmica.

solução:

τ=3500 J
Q1=5000J

η= τ/Q1
η= 3500/5000
η= 0,7 ou seja 70%

Energia dissipada será:

τ = Q1 - Q2
Q2 = Q1- τ

Q2=5000-3500
Q2= 1500 J

Exercicio: Qual seria o rendimento se a máquina do exercicio anterior realizasse 4000J de trabalho com a mesma quantidade de calor fornecida ? Quanta energia seria dissipada agora?

obs: Entregar foto da resolução ou o cálculo passo a passo na mensagem

4 0

3 years ago

what is the molarity of liters of an aqueous solution that contains 0.50 mole of potassium iodide, KI

Marizza181 [45]

Answer:

The molarity of 2.0 liters of an aqueous solution that contains 0.50 mol of potassium iodide is 0.25M.HOW TO CALCULATE MOLARITY:The molarity of a solution can be calculated by dividing the number of moles by its volume. That is;Molarity = no. of moles ÷ volumeAccording to this question, 2.0 liters of an aqueous solution that contains 0.50 mol of potassium iodide. The molarity is calculated as follows:Molarity = 0.50mol ÷ 2LMolarity = 0.25MTherefore, the molarity of 2.0 liters of an aqueous solution that contains 0.50 mol of potassium iodide is 0.25M.Learn more about molarity at: brainly.com/question/2817451

Explanation:

Mark me brainliest please!!! I spent a lot of time on this!!

5 0

2 years ago

What happens to the reactivity of nonmetals within a group from top of the group to the bottom?

andreev551 [17]

As you go down a group, the atoms get bigger. The bigger the atom, the more unstable it is. The more unstable it is, the more reactive the atom will be. So, as you go down a group, the nonmetals will become more reactive.

6 0

3 years ago

15 POINTS RIGHT NOW!!!!

Anettt [7]

Answer:

It is valid because his experiment had clear variables.

Explanation:

He had clear variables and did everyhting the same for both plants, even though he had calcium in one and not in the other, which gives him a true and good result.

5 0

3 years ago

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