<h3>
Answer:</h3>
- They show the elements of make up a compound
- They show the types of atoms that make up a molecule
- They show the number of each type of atom in a molecule
<h3>
Explanation:</h3>
To answer this question we need to know what is a compound.
- A compound is a substance that is made by two or more atoms of different elements that are chemically combined.
- A chemical formula of a compound is a formula that shows the elements that make up a compound and also the types of atoms that make up the molecule.
- Additionally, the chemical formula shows the number of each type of atom in a molecule.
- In this case, the chemical formula of a molecule of H₂O shows that it is made up of one hydrogen atom and two oxygen atoms.
The empirical formula of the compound is C. NiF₂.
<em>Step 1</em>. Calculate the <em>moles of each element</em>
The empirical formula is the simplest whole-number ratio of atoms in a compound.
The ratio of atoms is the same as the ratio of moles.
So, our job is to calculate the molar ratio of Ni to F.
Moles of Ni = 9.11 g Ni × (1 mol Ni /(58.69 g Ni) = 0.1552 mol Ni
Moles of F = 5.89 g F × (1 mol F/19.00 g F) = 0.3100 mol F
<em>Step 2</em>. Calculate the <em>molar ratio</em> of the elements
Divide each number by the smallest number of moles
Ni:F = 0.1552:0.3100 = 1:1.997 ≈ 1:2
<em>Step 3</em>: Write the <em>empirical formula</em>
EF = NiF₂
Answer:
6.It is concluded that while high temperature has an unfavourable effect on seed set of radish plants, it also weakens the incompatibility reaction between pollen and style, so that the result is a small increase in yield.
7.The result of the study showed that music with a higher intensity is more distracting and has a greater effect on task performance and concentration. The result helped formulate the Attention Drainage Effect theory, which is based on Kahneman's (1973) capacity model of attention
8. If the food is more colorful then the fish will eat more because they're more interested in the colors
9.If plants do not receive enough light, they will not grow at their maximum rate or reach their maximum potential, regardless of how much of any other variable – water, growth medium or fertiliser – they receive. Light is the driving force for photosynthesis, a plant process that changes sunlight into chemical energy. Plants need five things in order to grow: sunlight, proper temperature, moisture, air, and nutrients. These five things are provided by the natural or artificial environments where the plants live. If any of these elements are missing they can limit plant growth.
The independent (or manipulated) variable is something that the experimenter purposely changes or varies over the course of the investigation. The dependent (or responding) variable is the one that is observed and likely changes in response to the independent variable.
10.What effect does smiling have on a teacher giving no homework.
Hypothesis
If a student smiles at teacher, then no homework will be assigned
independent variable is smiling
dependent variable is homework
Explanation:
Answer:
Only
gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential (
) of the reaction is positive. Because it leads to negative standard gibbs free energy change (
), which is a thermodynamic condition for spontaneity of a reaction.
![E^{0}=E^{0}(reduction)-E^{0}(oxidation)](https://tex.z-dn.net/?f=E%5E%7B0%7D%3DE%5E%7B0%7D%28reduction%29-E%5E%7B0%7D%28oxidation%29)
Where
and
represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation:
; ![E_{Mg^{2+}\mid Mg}^{0}=-2.38V](https://tex.z-dn.net/?f=E_%7BMg%5E%7B2%2B%7D%5Cmid%20Mg%7D%5E%7B0%7D%3D-2.38V)
Reduction:
; ![E_{Fe^{3+}\mid Fe}^{0}=-0.04V](https://tex.z-dn.net/?f=E_%7BFe%5E%7B3%2B%7D%5Cmid%20Fe%7D%5E%7B0%7D%3D-0.04V)
So, ![E^{0}=E_{Fe^{3+}\mid Fe}^{0}-E_{Mg^{2+}\mid Mg}^{0}=(-0.04+2.38)V=2.34V](https://tex.z-dn.net/?f=E%5E%7B0%7D%3DE_%7BFe%5E%7B3%2B%7D%5Cmid%20Fe%7D%5E%7B0%7D-E_%7BMg%5E%7B2%2B%7D%5Cmid%20Mg%7D%5E%7B0%7D%3D%28-0.04%2B2.38%29V%3D2.34V)
Hence this pair will give spontaneous reaction.
(2) Similarly as above, ![E^{0}=E_{Pb^{2+}\mid Pb}^{0}-E_{Au^{+}\mid Au}^{0}=(-0.13-1.69)V=-1.82 V](https://tex.z-dn.net/?f=E%5E%7B0%7D%3DE_%7BPb%5E%7B2%2B%7D%5Cmid%20Pb%7D%5E%7B0%7D-E_%7BAu%5E%7B%2B%7D%5Cmid%20Au%7D%5E%7B0%7D%3D%28-0.13-1.69%29V%3D-1.82%20V)
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above, ![E^{0}=E_{Ag^{+}\mid Ag}^{0}-E_{Br_{2}\mid Br^{-}}^{0}=(0.80-1.07)V=-0.27 V](https://tex.z-dn.net/?f=E%5E%7B0%7D%3DE_%7BAg%5E%7B%2B%7D%5Cmid%20Ag%7D%5E%7B0%7D-E_%7BBr_%7B2%7D%5Cmid%20Br%5E%7B-%7D%7D%5E%7B0%7D%3D%280.80-1.07%29V%3D-0.27%20V)
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above, ![E^{0}=E_{Li^{+}\mid Li}^{0}-E_{Cr^{3+}\mid Cr}^{0}=(-3.04+0.74)V=-2.30 V](https://tex.z-dn.net/?f=E%5E%7B0%7D%3DE_%7BLi%5E%7B%2B%7D%5Cmid%20Li%7D%5E%7B0%7D-E_%7BCr%5E%7B3%2B%7D%5Cmid%20Cr%7D%5E%7B0%7D%3D%28-3.04%2B0.74%29V%3D-2.30%20V)
Hence this pair will give non-spontaneous reaction.