Because it’s called heat changes it and melts the ice
Answer:
an ion is an element that has different numbers of protons and electrons
Explanation:
An ion is positive when it has more protons than electrons and negative when it has more electrons than ions.
(Hope this was helpful!) :)
Answer:
C + O2 → CO2
Explanation:
C + O2 → CO ----------------- (1)
from equ (1) on reactant side, C has 1 mole, O has 2 moles
from equ (1) on product side, C has 1 mole, O has 1 mole
Thus, to balance the equation, O should have 2 moles
C + O2 → CO2
Answer:
pH = 3.3
Explanation:
Buffer solutions minimize changes in pH when quantities of acid or base are added into the mix. The typical buffer composition is a weak electrolyte (wk acid or weak base) plus the salt of the weak electrolyte. On addition of acid or base to the buffer solution, the solution chemistry functions to remove the acid or base by reacting with the components of the buffer to shift the equilibrium of the weak electrolyte left or right to remove the excess hydronium ions or hydroxide ions is a way that results in very little change in pH of the system. One should note that buffer solutions do not prevent changes in pH but minimize changes in pH. If enough acid or base is added the buffer chemistry can be destroyed.
In this problem, the weak electrolyte is HNO₂(aq) and the salt is KNO₂(aq). In equation, the buffer solution is 0.55M HNO₂ ⇄ H⁺ + 0.75M KNO₂⁻ . The potassium ion is a spectator ion and does not enter into determination of the pH of the solution. The object is to determine the hydronium ion concentration (H⁺) and apply to the expression pH = -log[H⁺].
Solution using the I.C.E. table:
HNO₂ ⇄ H⁺ + KNO₂⁻
C(i) 0.55M 0M 0.75M
ΔC -x +x +x
C(eq) 0.55M - x x 0.75M + x b/c [HNO₂] / Ka > 100, the x can be
dropped giving ...
≅0.55M x ≅0.75M
Ka = [H⁺][NO₂⁻]/[HNO₂] => [H⁺] = Ka · [HNO₂]/[NO₂⁻]
=> [H⁺] = 6.80x010⁻⁴(0.55) / (0.75) = 4.99 x 10⁻⁴M
pH = -log[H⁺] = -log(4.99 x 10⁻⁴) -(-3.3) = 3.3
Solution using the Henderson-Hasselbalch Equation:
pH = pKa + log[Base]/[Acid] = -log(Ka) + log[Base]/[Acid]
= -log(6.8 x 10⁻⁴) + log[(0.75M)/(0.55M)]
= -(-3.17) + 0.14 = 3.17 + 0.14 = 3.31 ≅ 3.3
Answer:
0.382 atm
Explanation:
In order to find the pressure, you need to know the moles of carbon dioxide (CO₂) gas. This can be found by multiplying the mass (g) by the molar mass (g/mol) of CO₂. It is important to arrange the conversion in a way that allows for the cancellation of units.
Molar Mass (CO₂): 12.011 g/mol + 2(15.998 g/mol)
Molar Mass (CO₂): 44.007 g/mol
15 grams CO₂ 1 mole
---------------------- x ------------------------ = 0.341 moles CO₂
44.007 grams
To find the pressure, you need to use the Ideal Gas Law equation.
PV = nRT
In this equation,
-----> P = pressure (atm)
-----> V = volume (L)
-----> n = moles
-----> R = Ideal Gas Constant (0.08206 atm*L/mol*K)
-----> T = temperature (K)
After you convert Celsius to Kelvin, you can plug the given and calculated values into the equation and simplify to find the pressure.
P = ? atm R = 0.08206 atm*L/mol*K
V = 20 L T = 0 °C + 273.15 = 273.15 K
n = 0.341 moles
PV = nRT
P(20 L) = (0.341 moles)(0.08206 atm*L/mol*K)(273.15 K)
P(20 L) = 7.64016
P = 0.382 atm
