In the reaction Mg (s) + 2HCl (aq) -> H2 (g) + MgCl2 (aq), how many grams of hydrogen gas will be produced from 300 milliliters of a 4 M HCl in an excess of Mg? Please show all work
Which is the best metal to use in an alloy to increase its electrical conductivity?Aluminum (Al) Silver (Ag) Zinc (Zn) Antimony (Sb)
Answers
Answer:
Its Silver!
Explanation:
I took a quiz, and i got it right!
How do you decide whether an observed property of matter is a physical or a chemical property?
Answers
By the object's composition and the acting agent to which factors the change of the substance or entity. The effect of physical property of matter on the object or substance can be better identified when the object doesn't change in composition or in nature. Unlike chemical property which has changed in its composition and atomic structure that was caused by chemical change or reaction due to an agent. Physical property is identified thru physical reactions or changes that has never changed the object in an atomic level, like cutting paper into smaller sizes. The aforementioned example illustrates physical proerty but being cut into smaller buts without changing the object from paper to any other substance, thus, its structure remain and its still called paper regardless of size, mass and texture.
Because a physical property doesn't change the substance if you apply it. A chemical property will change its matter into a new substance. Example of physical : cutting, because it will grow back to how it was Example of chemical : flammability because if you burn it.....it wont go back to its original form.
Explain, in terms of atomic structure, why the radius of an Na atom is larger than the radius of an Na+ ion.
Answers
In a Naatom, there are 11 protons controlling 11 electrons by electrostatic attraction. In Na+ there are 11 protons controlling 10 electrons (you lost one to give Na+), so they can pull them in tighter!!
How many molecules are in 2.6 grams H4C
Answers
Molar mass of H4C = 1 * 4 + 12 = 16 g/mol
Number of moles:
n = m / mm
n = 2.6 / 16
n = 0.1625 moles
Number of molecules:
number of moles * 6.02x10²³
0.1625 * 6.02x10²³
= 9.78x10²² molecules
hope this helps!
How does adding salt affect the freezing point of water?
Answers
One of the colligative properties of water is the freezing point depression. A colligative property is a change in the property of water due to some amount of solute. Adding salt will lower down the freezing point of water which means that more heat would be needed to bring the boil to freeze.
When adding salt, the more you add the freezing point drops. The sodium and chlorine ions from the salt get in the way of the water molecules. This makes it harder for them to be rearranged into crystals. Salt prevents ice from staying solid because it raises the temperature .
How does the hydrogen atom produce light
Answers
when energy is put into an atom, the electrons can use the energy to go to a higher energy state (n value) which is called an exited state. when the electron goes back down to where it started (called the ground state) it releases the energy it gained in the form of a photon which is why it produces light. A common way to get hydrogen gas to produce light is by passing an electric current through the sample.