If the element have 39 protons, that means that his atomic number is 39, being Yttrium the element. And, the number of protons is the same of the number of electrons, so, 39 electrons.
From equation;
P1V1=P2V2
V2=P1V1÷P2
since P2=380mmHg
now;1atm=760mmHg
how about 380mmHg is equal to how many atm?
380×1÷760=0.5atm
P2 now is equal to 0.5atm
back from equation;
P1V1=P2V2
V2=P1V1÷P2
V2=4.0atm×2.0L÷0.5atm
V2=16L
therefore V2=16L.
<span>1) </span><span>What is air pressure? (Answ</span>er: Atmospheric
pressure, sometimes also called barometric pressure, is the pressure within the
atmosphere of Earth.)
<span>2)
</span><span>What
is a barometer and what is it used to measure? <span>(Answer: A barometer is a scientific instrument used in meteorology to
measure atmospheric pressure. Pressure tendency can forecast short term changes in the
weather.)</span></span>
<span>3)
</span><span>How
does air pressure change? <span>(Answer: Millibar values used in
meteorology range from about 100 to 1050. At sea level, standard air pressure in millibars is
1013.2. Weather maps showing the pressure at
the surface are drawn using millibars. ... This change in pressure is
caused by changes in air density, and air density is related to
temperature.)</span></span>
<span>4) </span><span>Why is cooler, drier air related to High
Pressure? <span>(Answer: This is due to density differences
between the two air masses.
Since stronger high-pressure systems contain cooler or drier air, the air mass is denser and flows
towards areas that are warm or moist, which are in the vicinity of low pressure areas in advance of
their associated cold fronts.)</span></span>
<span>5)
</span><span>Why
is warm, moister air related to Low Pressure?
<span>(Answer: When air warms, its molecules scatter.
The air becomes
lighter and rises.)</span></span>
Answer:
With an understanding of the ideal gas laws, it is now possible to apply these principles to chemical stoichiometry problems. For example, zinc metal and hydrochloric acid (hydrogen chloride dissolved in water) react to form zinc (II) chloride and hydrogen gas according to the equation shown below:
2 HCl (aq) + Zn (s) → ZnCl2 (aq) + H2 (g)
Explanation:
HA ⇄ H⁺ + A⁻
so:
![\frac{[H^+][A^-]}{[HA]} = 1.5 x 10^{-5}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D%20%3D%201.5%20x%2010%5E%7B-5%7D%20%20)
and now:
= 1.5 x 10⁻⁵
x is considered very small compared to 0.15
x² = 2.25 x 10⁻⁶
x = 1.5 x 10⁻³
So [H⁺] = 1.5 x 10⁻³
pH = - log [H⁺] = - log (1.5 x 10⁻³) = 2.83
