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3 years ago

5)

Chemistry

1 answer:

Drupady [299]3 years ago

4 0

What amount of heat absorbs 50 g of steel (ce = 0.115 cal / g. ° C) that

does its temperature vary by 25 ° C?

Answer:

143.75cal

Explanation:

Given parameters:

Mass of steel = 50g

Specific heat capacity of the steel = 0.115cal/g°C

Temperature = 25°C

Unknown:

Amount of heat = ?

Solution:

The amount of heat to cause this temperature change is dependent on mass and specific heat capacity of the substance.

Amount of heat = m C (ΔT)

m is the mass

c is the specific heat capacity

ΔT is the temperature change

Now insert the parameters and solve;

Amount of heat = 50 x 0.115 x 25

Amount of heat = 143.75cal

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Which of the following is the correct set-up for the problem: How many grams of water will be produced from 3.2 moles of oxygen

suter [353]

Option C is the correct set of the problem for mass of water produced by 3.2 moles of oxygen and an excess ethene.

<h3>Reaction between oxygen and ethene</h3>

Ethene (C2H4) burns in the presence of oxygen (O2) to form carbon dioxide (CO2) and water (H2O) along with the evolution of heat and light.

C₂H₄ + 3O₂ ----- > 2CO₂ + 2H₂O

from the equation above;

3 moles of O₂ ---------> 2(18 g) of water

3.5 moles of O₂ ----------> x

$x = 3.2 \times [\frac{2 \ moles \ H_2O}{3 \ moles \ O_2} ] \times[ \frac{18.02 \ g \ H_2O}{1 \ mole \ H_2O} ]$

Thus, option C is the correct set of the problem for mass of water produced by 3.2 moles of oxygen and an excess ethene.

Learn more about reaction of ethene here: brainly.com/question/4282233

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2 years ago

david’s mom wants to calculate how much it will cost to drive from los angeles, ca, to san francisco, ca. gas costs $4.00 a gall

grin007 [14]

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3 years ago

Read 2 more answers

A buffer is composed of nh3 and nh4cl. How would this buffer solution control the ph of a solution when a small amount of a stro

Shkiper50 [21]

Answer:

According to Le-chatelier principle, equilibrium will shift towards left to minimize concentration of $OH^{-}$ and keep same equilibrium constant

Explanation:

In this buffer following equilibrium exists -

$NH_{3}(aq.)+H_{2}O(l)\rightleftharpoons NH_{4}^{+}(aq.)+OH^{-}(aq.)$

So, $OH^{-}$ is involved in the above equilibrium.

When a strong base is added to this buffer, then concentration of $OH^{-}$ increases. Hence, according to Le-chatelier principle, above equilibrium will shift towards left to minimize concentration of $OH^{-}$ and keep same equilibrium constant.

Therefore excess amount of $OH^{-}$ combines with $NH_{4}^{+}$ to produce ammonia and water. So, effect of addition of strong base on pH of buffer gets minimized.