Can anyone explain this to me?

Chemistry

1 answer:

Kipish [7]3 years ago

5 0

The answer is D, the definition of standard enthalpy of formation is as follows: when one mole of a substance in the standard state (1 atm of pressure and 298.15 K) is formed from its pure elements. The last two words being especially important to this question. We would rule out A, B and C all because the product is formed from a mixture of an element and a compound and not just of elements. In other questions the reactants may all be in elemental form so you must look at the products being one mole or the reactants not being in their standard state.

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An element X combines with oxygen to form a compound of formula XO2. If 24.0 grams of element X combines with exactly 16.0 grams

tensa zangetsu [6.8K]

Answer:

atomic mass of X is 48.0 amu

Explanation:

Let y be the atomic mass of X

Molar mass of O_2 is = 2×16 = 32 g / mol

X + O2 -----> XO_2

According to the equation ,

y g of X reacts with 32 g of O_2

24 g of X reacts with Z g of O_2

Z = ( 32×24) / y

But given that 24.0 g of X exactly reacts with 16.0 g of O_2

So Z = 16.0

⇒ (32×24) / y = 16.0

⇒ y = (32×24) / 16

y= 48.0

So atomic mass of X is 48.0 amu

4 0

3 years ago

2. In a well-known movie, Raiders of the Lost Ark, there is a famous scene in which the hero tries to outwit the designers of a

Bezzdna [24]

Answer:

I cant answer B, but I can answer A, and I don't think it is a scientifically reasonable plan.

Explanation:

The bag of sand weighs less than the gold statue, and yes the bag of sand seems like it would keep the trap from activating, but you would scientifically have to put something that was the same weight as the gold statue on the pedestal that the statue is on.

3 0

3 years ago

I2(g) + Cl2(g)2ICl(g) Using standard thermodynamic data at 298K, calculate the entropy change for the surroundings when 1.62 mol

galina1969 [7]

Answer:

The change in entropy of the surrounding is -146.11 J/K.

Explanation:

Enthalpy of formation of iodine gas = $\Delta H_f_{(I_2)}=62.438 kJ/mol$