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iVinArrow [24]
4 years ago
12

Give at least two ways to know if a reaction is endothermic or exothermic

Chemistry
1 answer:
mafiozo [28]4 years ago
5 0

Answer:

An exothermic reaction is a chemical reaction that releases energy by light or heat. Endothermic reaction is a chemical reaction that absorbs energy or heat from its surroundings

Explanation:

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What are some physical characteristics of the Sun?
Zolol [24]

the sun has a radius of 432,169 miles

5 0
3 years ago
If the crucible originally weighs 3.715 g and 2. 000 g of hydrate are added to it , what is the weight of the water that is lost
dimulka [17.4K]
For this, you need to know 1) the mass of the hydrate and 2) the mass of the anhydrous salt. Once you have both of these, you will subtract 1) from 2) to find the mass of the water lost.

From the problem, you know that 1) = 2.000 g.

Now you need to find 2). You know that your crucible+anhydrous salt is 5.022 g. To find just the anhydrous salt, subtract the mass of the crucible (3.715 g).

1) = 5.022 g - 3.715 g = 1.307 g

Now you can complete our original task.

Mass H2O = 2) - 1) = 2.000 g - 1.307 g = 0.693 g.


4 0
4 years ago
An object was placed into a container of water the arrow shows the thermal energy is flowing from the water to the object what i
posledela

Answer:

<em>The valid conclusion is:</em>

  • <u><em>D. the temperature of the object is increasing, while the temperature of the water is decreasing</em></u>

<u><em></em></u>

Explanation:

The answer choices are:

  • <em>A. the temperature of the object is decreasing, while the temperature of the water is increasing</em>
  • <em>B. the temperature of the object is decreasing, while the temperature of the water is decreasing</em>
  • <em>C. the temperature of the object is increasing, while the temperature of the water is increasing</em>
  • <em>D. the temperature of the object is increasing, while the temperature of the water is decreasing</em>

<em />

<h2>Solution</h2>

<em />

Thermal or heat energy always flows from the hotter substances to the cooler substances.

Thus, since the arrows show that the thermal energy is flowing from the water to the object, the water is losing thermal energy and the object is gaining thermal energy.

When an object gains thermal energy, and there is not involved a change of phase, the temperature of the object increases. Thus, the temperature of the object is increasing.

On the other hand, since water is losing thermal energy, and there is not involved a change of phase, the temperature of the water decreases.

Therefore, the correct conclusion is described by the option A:

  • <em>A. the temperature of the object is decreasing, while the temperature of the water is increasing</em>
3 0
3 years ago
a gas that has a volume of 28 liters a temperature of 45 c and an unknown pressure has its volume increased to 34 liters and its
emmasim [6.3K]

Answer:

2.52 atm

Explanation:

Change C to K.

Solve for P1=P2V2T2/V1T1

- Hope that helps! Please let me know if you need further explanation.

5 0
4 years ago
Calculate the initial molarity of MCHM in the river, assuming that the first part of the river is 7.60 feet deep, 100.0 yards wi
Effectus [21]

Answer:

[MCHM] = 7.52 M

Explanation:

This all about unit conversion

1 feet = 0.3048 meters

1 yard = 0.9144 meters

7.60 feet . 0.3048 = 2.31 meters deep

100 yd . 0.9144 meters = 91.44 meters long and 91.44 meters wide

In the river we have a volume of:

2.31 m . 91.44m . 91.44m = 19314.5  m³

1 dm³ = 1 L

1 dm³ = 0.001 m³

19314.5 m³ / 0.001 m³ = 19314542 L (The final volume of the river)

3.785 L = 1 gallon

In 19314542 L, we have (19314542 / 3.785) = 5102917 gallons

1 gallon = 128 oz

5102917 gallons . 128 = 653173376 oz

1 oz = 28.3495 g

653173376 oz . 28.495 = 1.86x10¹⁰ grams

Molar mass MCHM = 128 g/m

Moles of MCHM = 1.86x10¹⁰ grams / 128 g/m = 145312500 moles

Molarity = mol /L → 145312500 moles / 19314542 L = 7.52 M

7 0
4 years ago
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