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3 years ago

Based on the enthalpy changes given for the reactions, which reactions are endothermic? (check all that apply)

Chemistry

2 answers:

Stels [109]3 years ago

5 0

Answer:

Based on the given bond energies, what is the enthalpy change for the chemical reaction?

-352 kJ

-210 kJ

-176 kJ

-105 kJ

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Explanation:

7nadin3 [17]3 years ago

4 0

In an endothermic reaction, “delta H” is always positive, since the system is absorbing heat from its surroundings, not releasing into the surroundings like in an exothermic reaction where the delta H is always negative.

So our endothermic reactions would be the first (484kJ) and the last (92kJ).

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6. Which of the following statements correctly describes what happens to the diaphragm during an

Crank

Answer is B.

As the diaphragm contracts and flattens, it increases the volume of the thorax where the lungs are located. This results in a decrease in pressure (Boyle’s Law, if you know it) that creates a pressure gradient from outside to inside. This is what causes air to move into the lungs.

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3 years ago

Read 2 more answers

Nitric oxide, NO, is made from the oxidation of NH3, and the reaction is represented by the equation: 4NH3 + 5O2 → 4NO + 6H2O Wh

tamaranim1 [39]

Answer:

16.16g of O2.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

4NH3 + 5O2 → 4NO + 6H2O

Next, we shall determine the mass of NH3 and O2 that reacted from the balanced equation. This is illustrated below:

Molar mass of NH3 = 14 + (3x1) = 17g/mol

Mass of NH3 from the balanced equation = 4 x 17 = 68g

Molar Mass of O2 = 16x2 = 32g/mol

Mass of O2 from the balanced equation = 5 x 32 = 160g.

From the balanced equation above,

68g of NH3 reacted with 160g of O2.

Now, we can calculate the mass of O2 that will be required to react completely with 6.87 g of NH3. This is illustrated below:

From the balanced equation above,

68g of NH3 reacted with 160g of O2

Therefore, 6.87g of NH3 will react with = (6.87 x 160)/68 = 16.16g of O2.

Therefore, 16.16g of O2 is needed for the reaction.

4 0

3 years ago

A cart is rolling across the floor at a constant velocity of 2 m/s to the right. The cart is pushed again to the right, and it s

galben [10]

Answer: the answer is c.The unbalanced push causes the cart to speed up.

Explanation:

The application of an unbalanced force (the push) causes the cart to speed up. When the cart is in constant motion, the forces are balanced and there is no speeding up. Once an unbalanced force is added, the cart's speed changes.

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4 years ago

Read 2 more answers

Temperature is a measure of _____.

Rzqust [24]

Temperature is a measure of thermal energy. Like, how hot or cold something is. When testing a temperature, you would use a <em>thermometer</em>. A thermometer measures how hot or cold something is.

Hope this helps. :)

8 0

4 years ago

What mass of butane in grams is necessary to produce 1.5×103 kJ1.5×103 kJ of heat? What mass of CO2CO2 is produced? Assume the r

saul85 [17]

32.8 g of Butane is required and 99.3 g of CO₂ is produced

<u>Explanation:</u>

The above mentioned reaction can be written as,

C₄H₁₀(g) + 13 O₂(g) → 4CO₂(g) + 5 H₂O(g) where ΔH (rxn)= -2658 kJ

It is given that 1.5 × 10³ kJ of energy is produced, the original reaction says that 2658 kJ of heat is produced, which means that less than one mole of butane is used in the reaction.

That is

$$\frac{1500}{2658}=0.564 \text { moles }$ of butane reacted

Now this moles is converted into mass by multiplying it with its molar mass = 0.564 mol × 58.122 g / mol

= 32.8 g of butane.

Mass of CO₂ produced = 0.564 ×44.01 g /mol × 4 mol

= 99.3 g of CO₂

Thus 32.8 g of Butane is required and 99.3 g of CO₂ is produced

7 0

3 years ago