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Murrr4er [49]
3 years ago
5

What type of reaction occurs in a hand warmer? Exothermic Endothermic

Chemistry
1 answer:
storchak [24]3 years ago
8 0

Answer:

The reaction is exothermic.

Explanation:

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A gas mixture contains HBr, NO2, and C2H6 at STP. If a tiny hole is made in the container, which gas will effuse fastest? NO2 C2
Anarel [89]

Answer:

C2H6

Explanation:

Let us first consider the molar Masses of each gas

HBr - 80.91 g/mol

NO2 - 46.0055 g/mol

C2H6 - 30.07 g/mol

We must remember that the greater the molar mass of a gas the lesser its velocity and average kinetic energy.

Looking at the gases listed, C2H6 have the highest average kinetic energy at this temperature since it has the lowest molecular mass. This reasoning is directly derived from Graham's law of diffusion in gases.

Hence C2H6 will effuse fastest when a hole is made in the container. It also possess the greatest average kinetic energy because it has the lowest molecular mass.

5 0
3 years ago
Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How
Basile [38]

Answer:

B.) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom loses the electron.

Explanation:

Silicon is located in the 3rd row and 14th column in the periodic table. Arsenic is located in the 4th row and 15th column in the periodic table. This means that arsenic has one more valence electron than silicon. Since arsenic is located one row down from silicon, its valence electrons occupy higher energy orbitals.

Silicon maintains a crystal-like lattice structure. Each silicon atom is covalently connected to assume this shape. When silicon gains one extra electron from arsenic, it experiences n-type doping. This new electron is not tightly bound in the lattice structure. This allows it to move more freely and conduct more electricity. This can also be explained using band gaps. Silicon, which previously had an empty conduction band, now has one electron in this band. This lowers the band gap between the conduction and valence bands and increases conductivity.

5 0
2 years ago
1. To calculate the molarity of a solution, you need to know the moles of solute and the
evablogger [386]

Answer:

O volume of the solution

Explanation:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / volume of solution  in L

For example:

if we dissolve the 1 mole of NaCl to make the solution of volume 2 L. The molarity of solution is,

M = 1 mol / 2 L

M = 0.5 M

3 0
3 years ago
Which of the following is true about an abiotic resource?
aev [14]

Answer:

B. It is a nonliving resource.

Explanation:

The definition of abiotic is "nonliving," and examples of abiotic resources may include soil or water.

5 0
3 years ago
In order to reduce the exposure to organic solvents like turpentine, some art instructors recommend the students clean brushes a
kykrilka [37]
Generally speaking, organic molecules tend to dissolve in solvents that have similar physical properties. A good rule of thumb is that "like dissolves like". Meaning, polar compounds can dissolve polar compounds and nonpolar compounds can dissolve nonpolar compounds.

To apply this to the current problem, we are told that the brushes are being cleaned with vegetable oil or mineral oil. In this case, the oils are used as solvents. In order for these solvents to be effective, the compounds they are trying to dissolve must be similar in structure and properties to other oils. Therefore, vegetable oil or mineral oil will be most effective in removing oil-based paints, as these will have the similar properties needed to dissolve in the oil solvents.
6 0
3 years ago
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