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Chemistry
This category encompasses all questions about the composition, structure, properties, and reactions of matter.
229,206 Questions
When matter changes state what two things are always conserved?
The Law of Conservation of Mass.
&
The Law of Conservation of Energy.
Aqueous. (Dissolved in water) Example: CaCl2(aq)= Aqueous Calcium Chloride.
Is nitrate a metal or a nonmetal?
Silver nitrate is a compound. It consists of the metal silver and the compound nitrate. Nitrate consists of nitrogen and oxygen.
Flame Test colour of 'lilac' (pale purple) indicates the present of potassium cations (K^(+)).
The Halogen test giving a cream(pale yellow) precipitation indicates the presence of bromide anions (B^(-)).
Hence for the given tests the substance is potassium bromide (KBr).
NB The is a comprehensive list of flame test colours in Wikipedia/
NNB Use Silver nitrate to test for halogen anions.
Fluoride (F^(-)) No ppt
Chloride (Cl^(_)) White ppt
Bromide (Br^(-)) Cream(pale yellow) ppt
Iodide (I^(-)) Bright yellow ppt.
Astatide (At^(-)) Not characterised. (Possibly green/dirty grey-yellow).
What can a flame test tell you about a certain compound?
No, because non metal atoms do not enter an excited state.
What does the flame test tell you about chemicals?
The 'Flame Test' tells you which cation is present. Thereby the given metal.
Flame test for ;-
Sodium(Na^(+)) ; Bright yellow flame
Potassium(K^(+)) ; Lilac flame
Copper (Cu^(2+)); Blue/Green flame
There are many more colours for Flame tests. You will find a list in Wikipedia.
To find the cation .
Dissolve the chemical in say nitric acid.
Wipe a ni-chrome/ platinum wire into the solution.
Pass the wire through a roaring (air hole open) Bunsen flame.
Notice the colour of the flame.
Refer to a list of cation flame test colours.
How can you tell if a chemical reaction is happening in a test tube?
You can identify a chemical reaction in a test tube by observing changes such as color shifts, the formation of a gas (bubbles), or the production of a precipitate (solid) that was not present before. Additionally, changes in temperature or the release of light can also indicate a reaction. If the substances mix and exhibit new properties, it’s a strong sign that a chemical reaction is occurring.
Which of these is the lightest chemical element?
Hydrogen is the least massive (lightest) chemical element.
It has an atomic mass of '1'
What is the atomic number of the chemical element hydrogen?
Hydrogen
Symbol ; ' H '. (Capital letter).
Atomic No, 1.
Atomic Mass ; 1
Are molecules are joined together to form elements?
NO!!!!
You have it the wrong way around. !!!
Elements in the form of atoms join together to form molecules.
What C contains different elements Joined toghether?
A compound is a substance composed of two or more different elements chemically joined together. This joining of elements creates a new substance with unique properties.
Is frost an example of sublimation?
No, frost is not an example of sublimation. Frost forms through the process of deposition, where water vapor in the air transitions directly into solid ice crystals without becoming liquid first. Sublimation, on the other hand, is the process where a solid turns directly into a gas, such as ice turning into water vapor without melting.
What is the atomic number of an atom of an element with 5 protons and 6 electrons?
Disregard the electrons, as their relative mass is insignificant to that of protons and neutrons. To find atomic mass, add the numbers of protons and neutrons: 5 + 6 = 11 is the mass number.
Which element has the letters AU as its chemical symbol?
There is no element with the symbols ' AU'.
'A' is Not used.
'U' is Uranium .
However, I think you mean 'Au '. (Aurum, which is the Latin name for Gold).
NB When writing elemental symbols , Single letter symbols are ALWAYS a CAPITAL Letter. Double letter symbols are , first letter is a CAPITAL letter, and the second letter is small/lower case'.
Since gold is a double letter symbol it is written as 'Au '. NOT 'AU'.
What is the name of the compound H2C2O4?
Ethane-di-oic Acid (Oxalic Acid)
Structurally,
H-O-(O=)C-C(=O)=O-H
What is the name compound for BaSO5?
No such compound as ' BaSO5 '.
If you mean ' BaSO4 '. it is barium sulphate.
Why is barium sulfate used in X-rays?
Barium sulphate is opaque to electro-magnetic waves of the x-ray wavelength. Just like a brick wall is opaque to electro-magnetic waves of the white light wavelength.
It creates a 'shadow' from which radi-ographers can see any problems.
What 2 substances contain iron?
No elements are made up of a compound. I think you mean 'Which elements make up iron oxide?', and the answer to that is iron and oxygen.
What is the cation symbol for FeCl2?
The symbol of the cation of FeCl2 is Fe2+. A cation is a positively charged ion and to find the formula of any compound you must balance the cations with the anions.
What is the symbol of cation of LiBr?
LiBr is a neutraliy charged ionic molecule
The cation is lithium and its symbol is ' Li^(+) '.
The anion is bromide and its symbol is ' Br^(-) '.
Is the neutralization reaction of hydrochloric acid and calcium chloride acid base or neutral?
Hydrochloric Acid and Calcium chloride does NOT react, because of the 'common ion' effect ( chloride).
