The amount of chemical energy is equal to the amount of heat and light energy.

This is due to the principle of conservation of energy, which states that the total energy of a system remains constant.

4 0

3 years ago

4. An 82 kg hiker climbs Mt. Humphrey near Flagstaff. During a two hour period, the hiker's

bazaltina [42]

Answer:

$\Delta E = 434253.96\,J$ , $\Delta P = 60.313\,W$

Explanation:

The change in energy is given by the change in gravitational potential energy:

$\Delta E = m\cdot g \cdot \Delta h$

$\Delta E = (82\,kg)\cdot (9.807\,\frac{m}{s^{2}} )\cdot (540\,m)$

$\Delta E = 434253.96\,J$

The average rate of change in terms of time is approximately this:

$\Delta P = \frac{\Delta E}{\Delta t}$

$\Delta P = \frac{434253.96\,J}{(2\,h)\cdot (\frac{3600\,s}{1\,h} )}$

$\Delta P = 60.313\,W$

8 0

3 years ago

A formic acid buffer solution contains 0. 20 m h c o o h hcooh and 0. 24 m h c o o − hcoox−. the pka of formic acid is 3. 75. wh

irina1246 [14]

A buffer solution contains an equivalent amount of acid and base. The pH of the solution with an acid dissociation constant (pKa) value of 3.75 is 3.82.

The amount of hydrogen or the proton ion in the solution is expressed by the pH. It is given by the sum of pKa and the log of the concentration of acid and bases.

Given,

Concentration of salt [HCOO⁻] = 0.24 M

Concentration of acid [HCOOH] = 0.20 M

The acid dissociation constant (pKa) = 3.75

pH is calculated from the Hendersons equation as,

pH = pKa + log [salt] ÷ [acid]

pH = 3.75 + log [0.24] ÷ [0.20]

= 3.75 + log (1.2)

= 3.75 + 0.079

= 3.82

Therefore, 3.82 is the pH of the buffer.

Learn more about pH here:

brainly.com/question/27181245

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6 0

2 years ago