Physical science, is the study of the composition, structure, properties and change of matter.[1][2] Chemistry is chiefly concerned with atoms and their interactions with other atoms - for example, [ the properties of the chemical bonds formed between atoms to create chemical compounds. As well as this, interactions including atoms and other phenomena - electrons and various forms of energy—are
Answer: Adenine and guanine are the two purines and cytosine, thymine and uracil are the three pyrimidines. The main difference between purines and pyrimidines is that purines contain a sixmembered nitrogencontaining ring fused to an imidazole ring whereas pyrimidines contain only a sixmembered nitrogencontaining ring. They both are types or categories of nitrogen containing bases present in nuclei acids of DNA and RNA.
Purines are 2 Ring or Carbon Ring, Nitrogen containing bases. That consist of these 2 rings next placed next to each other. These examples include - Adenine and Guanine.
Pyrimidines are 1 or single Ring Nitrogen containing structures. There are 3 nitrogenous bases that are categorized as pyrimidines. Cytosine, Thymine, and Uracil.
The answer
<span>he chemical reaction CrF3+H3PO4 → CrPO4 + 3HF
the main formula is
when we observe a reaction as follow:
XY + ZT --------------- XT + YZ
this is classified as double replacement reactions, this means: </span>two ionic compounds exchange ions, producing 2 new ionic compounds.
in our case we have CrF3+H3PO4 → CrPO4 + 3HF
so the classification is double-replacement reactions
Answer:
The acid must be a concentrated acid
Explanation:
Ethene is prepared in the laboratory by heating ethanol with excess concentrated tetraoxosulphate VI acid at 170°C . The reactionoccursc in two stages;
1) when the ethanol and sulphuric acid are mixed in a ratio of 1:2, ethyl hydrogentetraoxosulpate VI is formed
2) The compound formed in the first step is heated in the presence of excess concentrated sulphuric acid to give ethene and sulphuric acid.
The overall reaction can be perceived as the dehydration of ethanol. The gas produced (ethene) is usually passed through sodium hydroxide solution to remove any gaseous impurities present.
concentrated sulphuric acid is used in this process since it is a good dehydrating agent.
Reactants + Energy → Products. Note: ΔH represents the change in energy. In endothermic reactions, the temperature of the products is typically lower than the temperature of the reactants. ... The energy needed for the reaction to take place comes from the water, which gets colder as the reaction proceeds.
