Look up chromium on periodic table.
It's atomic number is 24.
It gives number of protons in an element.
Since the atom is uncharged (no extra or subtracted electrons), the number of protons will equal the number of electrons.
Answer : The correct option is (A).
Explanation :
- Endothermic reaction : When two liquids are combine into a flask, then the flask feels cold when we touch it because the system absorbed heat from the surrounding.
In general, endothermic process absorbs heat and cool the surrounding.
- Exothermic reaction : When two liquids are combine into a flask, then the flask feels hot when we touch it because the system released heat into the surrounding.
In general, exothermic process releases heat and rise the temperature of surrounding.
<span>The </span>standard enthalpy of formation<span> <span>is defined as the change in </span></span>enthalpy<span> <span>when one mole of a substance in the </span></span>standard<span> <span>state (1 atm of pressure and temperature of 298.15
K) is </span></span>formed<span> <span>from its
pure elements under the same conditions.</span></span>
C = pK
<span>C = 4.4E-4*0.032 = about 1.41E-5 </span>
<span>H2CO3 ==> H^+ + HCO3^- </span>
<span>k1 = (H^+)(HCO3^-)/(H2CO3) </span>
<span>(H^+)= (HCO3^-) = x </span>
<span>(H2CO3) = 1.41E-5 </span>
<span>Solve for x = (H^+) and convert to pH. </span>
