Answer:
b. HCOOH/ NaHCOO.
Explanation:
A buffer system may be formed in one of two forms:
- A weak acid with its conjugate base.
- A weak base with its conjugate acid.
Chose the pairs below that you could use to make a buffered solution.
a. HCI/NaOH. NO. HCl is a strong acid and NaOH is a strong base.
b. HCOOH/ NaHCOO. YES. HCOOH is a weak acid and HCOO⁻ (coming from NaHCOO) is its conjugate base.
c. HNO₂/H₂SO₃. NO. Both are acids and they are unrelated to each other.
d. NaNO₃/ HNO₃. NO. HNO₃ is a strong acid.
Answer:
The second student is right.
Explanation:
The coyote feed on not only phalaropes but many other organisms present in the environment for its survival. There are many other organisms present in the ecosystem such as mice, squirrel, cactus fruit etc. The coyote feeds on phalaropes, the phalaropes feeds on brine shrimp and the brine shrimp feeds on algae for its survival so in this way the ecosystem moves in the forward direction. The coyote feeds on phalaropes so the energy that is present in phalaropes transferred into coyote which only 10 % while the remaining is released in the atmosphere in the form of heat energy.
Answer:
Fluorine
Explanation:
Fluorine is assigned the oxidation number of -1 because it attracts the electrons in the bond more strongly than carbon does. Fluorine appears to have an extra electron, -1 oxidation number.
Fluorine is the most electronegative element on the periodic table.
Answer:
3.1 x 10⁻²¹ Nm
Explanation:
When placed in an external electric filed, an electric dipole experiences a torque. and this torque is represented mathematically with the equation:
torque (τ) = dipole moment vector (P) x electric field vector (E)
τ = P. E . sin θ
where θ is the angle between the water molecule and the electric field, which in this case is 90° (because this is where the torque is maximum)
τ = 6.2x10⁻³⁰Cm . 5.0x10⁸ N/C . sin90
τ = 6.2x10⁻³⁰Cm . 5.0x10⁸ N/C . 1
solve for τ
τ = 3.1 x 10⁻²¹ Nm
the maximum possible torque on the water molecule is therefore 3.1 x 10⁻²¹ Nm
