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3 years ago

Can somebody plz help answer this science questions (only 1-2 sentences is good thx !

Chemistry

1 answer:

Mrac [35]3 years ago

8 0

I believe it’s because they are trying to find other things that won’t pollute the environment as much, and they are also doing this because we are trying to reduce green house gas. Sorry if i’m wrong :(

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An unknown metal displaces Ali from solution but does not displace sodium using the activity series determine the unknown metal

MAXImum [283]

Answer:

The reactivity of metal is determined by the reactivity series. ... The metal which easily displaced aluminium will lie above in the series but that same element cannot displace sodium, so it will lie below in the series. Hence, from the series, we conclude that the unknown metal could be calcium or magnesium.

Explanation:

Hope this helps! :)

8 0

2 years ago

The major source of aluminum in the world this bauxite (mostly aluminum oxide). It’s thermal decomposition can be represented by

Artyom0805 [142]

Answer:

The correct answer is 32.2 grams.

Explanation:

Based on the given information, the enthalpy of formation for aluminum oxide is 1676 kJ/mol. It signifies towards the energy that is required to generate aluminum and oxygen, and both of these exhibit zero enthalpy of formation. Therefore, the ΔHreaction is the required energy to generate 2 moles of aluminum. Thus, the energy needed for the formation of single mole of aluminum is,

ΔHrxn = 1676/2 = 838 kJ/mol

Q or the energy input mentioned in the given case is 1000 kJ. Therefore, the number of moles of Al generated is,

(1000 kJ) / (838 kJ/Al mole) = 1.19 moles of Aluminum

The grams of aluminum produced can be obtained by using the formula,

mass = moles * molecular mass

= 1.19 * 26.98

= 32.2 grams.

7 0

3 years ago

Butane C4H10 (g),(Hf = –125.7), combusts in the presence of oxygen to form CO2 (g) (Delta.Hf = –393.5 kJ/mol), and H2O(g) (Delta

shusha [124]

Answer: The enthalpy of combustion, per mole, of butane is -2657.4 kJ

Explanation:

The balanced chemical reaction is,

$2C_4H_{10}(g)+13O_2(g)\rightarrow 8CO_2(g)+10H_2O(g)$

The expression for enthalpy change is,

$\Delta H=[n\times H_f_{products}]-[n\times H_f_{reactants}]$

Putting the values we get :

$\Delta H=[8\times H_f_{CO_2}+10\times H_f_{H_2O}]-[2\times H_f_{C_4H_{10}+13\times H_f_{O_2}}]$

$\Delta H=[(8\times -393.5)+(10\times -241.82)]-[(2\times -125.7)+(13\times 0)]$

$\Delta H=-5314.8kJ$

2 moles of butane releases heat = 5314.8 kJ

1 mole of butane release heat = $\frac{5314.8}{2}\times 1=2657.4kJ$

Thus enthalpy of combustion per mole of butane is -2657.4 kJ

3 0

3 years ago

Can someone help.? thanks :)

laila [671]

Answer:

1. Equation: 2x + 3 = 9x - 11

2. Each row has 2 chairs

Explanation:

The variable x represents the number of chairs in each row.

1. She can form 2 rows of a given length with 3 chairs left over.

Thus, she has:

number of rows number of chairs in chairs number of chairs

each row left over she has

2 x 3 2x + 3

2. She can form 9 rows of the same length if she gets 11 more chairs.

That means that she is short in 11 chairs to have 9x chairs, or that she has 11 less chairs than 9x chairs. Then she has:

9x - 11

3. Equation:

Then, number of chairs she has is 2x + 3 and, also, 9x - 11, which allows to set the equation:

2x + 3 = 9x -11

4. Solve the equation:

9x - 2x = 3 + 11

7x = 14

x = 2

Therefore, each row has 2 chairs, and she has 2x + 3 = 4 + 3 = 7 chairs.

4 0

3 years ago

_____________________ are trying to create better batteries that can store more energy, so that electric cars can travel further

lidiya [134]

Answer:

options?

Explanation:

i mean scientists fits so if any of the options have a scientist thats it

8 0

2 years ago

Read 2 more answers