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3 years ago

Based on the enthalpy changes given for the reactions, which reactions are endothermic?

Chemistry

1 answer:

aksik [14]3 years ago

6 0

Answer:

the first and last

Explanation:

the enthalpy Change is positive.

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Neutrons have. a.negative b.positive c.no charge d.nucleus

Firdavs [7]

A negative That's the answer

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4 years ago

Which gas is produced when dilute hydrochloric acid is added to a reactive metal.

Digiron [165]

Hydrogen gas is produced when dilute hydrochloric acid is added to a reactive metal.

Balanced molecular equation of sodim metal with hydrochloric acid:

2Na(s) + 2HCl(aq) → 2NaCl(aq) + H₂(g).

Ionic equation: 2Na(s) + 2H⁺(aq) + 2Cl⁻(aq) → 2Na⁺ + 2Cl⁻(aq) + H₂(g).

Net ionic equation: 2Na(s) + 2H⁺(aq) → 2Na⁺(aq) + H₂(g).

Sodium is oxidized from oxidation number 0 (Na) to oxidation number +1, hydrogen is reduced from oxidation number +1 to oxidation number 0 (hydrogen gas H₂).

Another example:

Balanced chemical equation: Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

Word equation: zinc + hydrochloric acid → zinc chloride + hydrogen gas

More about hydrogen gas:brainly.com/question/24433860

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2 years ago

Consider an ideal gas at 30 ∘C and 1.02 atm pressure. To get some idea how close these molecules are to each other, on the avera

Nastasia [14]

Answer: They are close to each other by 41.03 m^3

Explanation:

From Ideal gas equation, PV = nRT

Where n is negligible

R is gas constant = 8.314 J/mol.k

T = 30 + 273 = 303K

P = 1.02 * 103351.5 = 103351.5 Pascal

Then;

PV = RT

V = P/RT

V = 103351.5/(8.314*303)

V = 41.03m^3

8 0

3 years ago

Read 2 more answers

The average propane cylinder for a residential grill holds approximately 18 kg of propane. How much energy (in kJ) is released b

brilliants [131]

Combustion is a chemical reaction between a fuel and an oxidant, oxygen, to give off combustion products and heat. Complete combustion results when all of the fuel is consumed to form carbon dioxide and water, as in the case of a hydrocarbon fuel. Incomplete combustion results when insufficient oxygen reacts with the fuel, forming soot and carbon monoxide.

The complete combustion of propane proceeds through the following reaction:
$C_{3} H_{8}$ + $5O_{2}$ --> $3CO_{2}$ + $4H_{2}O$

Combustion is an exothermic reaction, which means that it gives off heat as the reaction proceeds. For the complete combustion of propane, the heat of combustion is (-)2220 kJ/mole, where the minus sign indicates that the reaction is exothermic.

The molar mass of propane is 44.1 grams/mole. Using this value, the number of moles propane to be burned can be determined from the mass of propane given. Afterwards, this number of moles is multiplied by the heat of combustion to give the total heat produced from the reaction of the given mass of propane.

14.50 kg propane x 1000 g x 1 mole propane x 2220 kJ 
1 kg 44.1 g 1 mole

= 729,931.97 kJ

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3 years ago

Why can metals be extracted using carbon

8090 [49]

If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.

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2 years ago