The answer is C. sugar water. Sugar can dissolve in water completely and form the solution. While other three are all heterogeneous mixture.
C=λν ==> λ=c/ν
λ= 3x10^8 m/s / 1.50 x 10^15 s^-1
λ= 2 x 10^-7 m
λ= 200 nm
Answer:
D) a salt bridge
Explanation:
A salt bridge completes an electrochemical cell. A salt bridge maintains charge balance in the two half cells. If the salt bridge is not present, the anode compartment becomes positively charged while the cathode compartment becomes negatively charged hence the reaction reaches equilibrium and comes to a halt quickly.
Answer:
H-O-H polar
O-C-O nonpolar
H-C-N polar
Explanation:
Looking up the electronegativities of the atoms involved in this question, we have:
Atom Electronegativity
H 2.2
C 2.55
N 3.04
O 3.44
All of the atoms differ in electronegativity resulting in individual dipole moments in H-O, O-C, H-C and C-N bonds. To find if the molecules will be polar we need to consider the structure of the compound to see if there is a resultant dipole moment.
In H-O-H, we have 2 lone pairs of electrons around the central oxygen atom which push the angle H-O-H of the ideal tetrahedral structure to be smaller than 109.5 º resulting in an overall dipole moment making it polar.
In O-C-O, we have two dipole moments that exactly cancel each other in the linear molecule since the central carbon atom does not have lone pairs of electrons since it has 2 double bonds. Therefore the molecule is nonpolar.
In H-C-N, again we have have a central carbon atom without lone pairs of electrons and the shape of the molecule is linear. But, now we have that the dipole moment in C-N is stronger than the H-C dipole because of the difference in electronegativity of nitrogen compared to hydrogen. The molecule has an overall dipole moment and it is polar.
