Craters are due to impact of meteorites. it could be that at that certain time, there were more meteorites that landed on that area than other places.
A rain gauge is really just a cylinder that catches rain. If an inch collects in the cylinder, it means an inch of rain has fallen. It's that simple. Most standard rain gauges have a wide funnel leading into the cylinder and are calibrated so that one-tenth of an inch of rain measures one inch when it collects inside.
H2O is the substance that has the strongest intermolecular forces.
Answer:
C. hydrocyanic acid
Explanation:
The mixture of a weak acid (As hydrocyanic acid, HCN), with its conjugate base (Na⁺CN⁻) produce a buffer effect in the solution due the equilibrium:
HCN ⇄ CN⁻ + H⁺
Now, when NaOH (A base) is added to the mixture, the reaction with <em>HCN </em>is:
NaOH + HCN → Na⁺CN⁻ + H₂O
As the OH⁻ of NaOH are not affecting directly the H⁺ concentration, <em>the pH does not increase dratically.</em>
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Right answer is:
<em>C. hydrocyanic acid
</em>
Answer is: 0,327 g/l.
<span>Ideal gas law: pV = nRT.
</span><span>V - volume, the amount of space occupied by the gas.
</span><span>p - pressure ,1 atm = 760 torr = 760 mmHg.
</span><span>n - amount of substance.
</span>T - temperature, 273 K = 0°<span>C. T = 25 + 273 = 298K.
</span>R - ideal gas constant,<span> R = 0,08206 L</span>·atm/mol·K<span>.
</span>d(He) = M·p ÷ R·T.
d - density.
M - molar mass.
d(He) = 4g/mol · 2atm ÷ 298K · 0,08206 L·atm/mol·K = 0,327 g/l.