Answer:
17)A. Solids
18) A. Frequently collide with each other and with surface of ballon
19) D. Particles are smaller at lower pressure.
1374.75 is the concentration in milligrams per ml of a solution containing 23.5 meq sodium chloride per milliliter.
Concentration in chemistry is calculated by dividing a constituent's abundance by the mixture's total volume.
It is calculated in mg/ml.
The unit of measurement frequently used for electrolytes is the milliequivalent (mEq). This value compares an element's chemical activity, or combining power, to that of 1 mg of hydrogen.
Formula for calculating concentration in mg/ml is
Conc. (mg/ml) = M(eq) /ml × Molecular weight / Valency
Given
M(eq) NaCl/ ml = 23.5
Molecular weight pf NaCl = 58.5 g/mol
Valency = 1
Putting the values into the formula
Conc. (mg/ml) = 23.5 ×58.5/1
= 1374.75 mg/ml
Hence, 1374.75 is the concentration in milligrams per ml of a solution containing 23.5 meq sodium chloride per milliliter.
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Answer: Positive effects: mass production of fertilizers, alkaline cleansers, refrigerant gas, dyes, explosives
Negative effects: heath problems, negative effects on soil organisms and soil organic matter, imbalances to the nitrogen cycle, high fossil fuel energy inputs, production of deadly weapons
Explanation:
The Haber process (also called Haber Bosch process) is used to produce ammonia from nitrogen and hydrogen under the high pressure. Basically, it's an artificial nitrogen fixation process. This method has both positive and negative effects on modern society.
Positive sides: ammonia is mainly used for mass production of fertilizer, which allows more food for everyone. It can be used for production of alkaline cleansers, refrigerant gas, dyes and explosives. Ammonia is also used in production of synthetic polymers, due to its role in the manufacturing of cyanide.
Negative sides: ammonia is a toxic gas, it can irritate eyes and lungs. Because of that, the excess nitrogen in soil and water coming from synthetic fertilizers can cause health problems. It is harmful for humans and animals, but it can also be harmful for plants. Environmental factors are also important. Because of the mass fixation, there is imbalance in the earth’s nitrogen cycle. Also, fossil fuels are used as a source of power for machinery in Haber's process, which increases emissions into the atmosphere. And, at least ammonia is a major component of weapons including great number of bombs.
The heat released by the substance in the calorimeter is equal to the heat absorbed by water which results to the decrease and increase in temperature, respectively.
We use m Cp ΔT to balance the heat involved
(m Cp ΔT) subs in calorimeter = <span>(m Cp ΔT) water
</span>125 g * Cp * (97.0-23.5 ) C = 250 g *(4.18 J/C g)* (23.5-20)
Cp = 0.398 J/Cg
Answer is B