Answer:
We have to fill the acetylene tank with a pressure of 60.67 atm to ensure that you run out of each gas at the same time
Explanation:
Step 1: Data given
Volume of tank 1 = 6.50 L = oxygen
Volume of tank 2 = 4.50 L = acetylene
Pressure in the oxygen tank = 105 atm
Step 2: The balanced equation
2 C2H2 + 5 O2 → 4 CO2 + 2 H2O
For 2 mol C2H2 we need 5 moles O2 to produce 4 moles CO2 and 2 moles H2O
Step 3: Calculate the pressure of the acetylene tank
For 2 mol C2H2 we need 5 moles O2 to produce 4 moles CO2 and 2 moles H2O
This means for each 5 moles O2 we have 2 moles acetylene
Pressure (105 atm) * (2/5) * (6.50 / 4.50) = 60.67 atm
We have to fill the acetylene tank with a pressure of 60.67 atm to ensure that you run out of each gas at the same time
69. The student's skin was obviously warmer than the initial temperature of the bracelet. According to the second law of thermodynamics, heat transfers from a higher temperature to a lower temperature hence heat transfers from the student's skin to the bracelet warming up the bracelet.
70. moles of copper=mass of copper/molar mass of copper
=30.1g/(63.55g/mol)= 0.4736 moles Cu
71. Delta H( heat released) = mCp(deltaT) = 30.1g(0.385 J/gK)(33-19)K = 162.23J
72. Copper is chemically less active than iron.
Answer:
Potassium (K) has a larger average atomic radius (220 pm) than sodium (Na) does (180 pm). The potassium atom has an extra electron shell compared to the sodium atom, which means its valence electrons are further from the nucleus, giving potassium a larger atomic radius. The ionic radius increases in a particular group on moving from top to bottom due to increase in the principle energy shell though the number or electrons in the valence shell remain the same
To get the ratio of the concentration of sodium acetate to the concentration of acetic acid we are going to use H-H equation:
when:
PH = Pka + ㏒[salt/acid]
when the Ka of acetic acid = 1.75 x 10^-5
so, we can get Pka from this formula:
Pka = -㏒Ka
= -㏒1.75 x 10^-5
= 4.76
and when we have PH = 5.75, so by substitution:
∴ 5.75 = 4.76 + ㏒[acetate/ acetic acid]
∴ [acetate/acetic acid] = 9.77
∴ the ratio of a concentration of acetate to acetic acid 9.77
