3.85 :) .....................................................................
Answer: The final energy is 1,700 J
Explanation: According to first law of thermodynamics:

=Final energy-initial energy=Change in internal energy
q = heat absorbed or released
w = work done by or on the system
w = work done by the system=
{Work done by the system is negative as the final volume is greater than initial volume}
q = +500J {Heat absorbed by the system is positive}
w = work done by the system = -300J


Answer:
197mL of 0,506M HCl
Explanation:
The reaction of HCl + BaCO₃ is:
BaCO₃(s) + 2HCl → BaCl₂(aq) + CO₂ + H₂O.
The moles of BaCO₃ in 9,85 g are:
9,85 g of BaCO₃ ×
= <em>0,0499 moles of BaCO₃</em>
As 1 mol of BaCO₃ reacts with two moles of HCl, for a complete reaction of BaCO₃ to dissolve this compound in water you need:
0,0499 moles of BaCO₃ ×
=<em> 0,0998 moles of HCl</em>
If you have a 0,506M HCl, you need to add:
0,0998 moles of HCl×
= 0,197 L ≡ 197mL
I hope it helps!
C. It increases and the pH stays constant.
Answer:
227 mmHg
Explanation:
Ptotal= PCO2 +PAr+PO2+PHe
PHe= Ptotal-PCO2 -PAr-PO2
PHe= (770 mmHg)-(128 mmHg)-(232 mmHg)-(183 mmHg)
PHe=227 mmHg