Answer:
Endothermic reaction
Explanation:
Endothermic reactions are defined as the type of chemical reaction in which the system absorbs the energy from the surroundings and the temperature of the surrounding decreases while in Exothermic reactions, heat is released by the system to the surroundings and it makes the surrounding warm.
The given example is an "endothermic reaction" because the reaction between NH4Cl and water is making the surrounding cool (cold pack) due to the release of heat.
Hence, the correct answer is "endothermic reaction".
The empirical formula is N₂O₅.
The empirical formula is the <em>simplest whole-number ratio of atoms</em> in a compound.
The ratio of atoms is the same as the ratio of moles, so our job is to calculate the <em>molar ratio of N:O</em>.
I like to summarize the calculations in a table.
<u>Element</u> <u>Moles</u> <u>Ratio¹ </u> <u> ×2² </u> <u>Integers</u>³
N 1.85 1 2 2
O 4.63 2.503 5.005 5
¹To get the molar ratio, you divide each number of moles by the smallest number (1.85).
²Multiply these values by a number (2) that makes the numbers in the ratio close to integers.
³Round off the number in the ratio to integers (2 and 5).
The empirical formula is N₂O₅.
Answer
The components of the r group of amino acid structure varies among different amino acids
Explanation
As the functional group for amino acids is as:
R-CH-COOH
I
NH2
only R differs so amino acids also differs. If R is “H” then amino acid is glycine and if R is “CH3” then amino acid is alanine. Hence, R is different for different amino acids. Other components as alpha carbon ( C ), carboxyl group ( COOH ) and amino group ( NH2 ) is fixed for every amino acid.
Answer:
C. 2&3 created a chemical change
Explanation:
Answer:
Sodium
Explanation:
Sodium is a pure chemical, hence it can be represented by the single chemical symbol Na.
Water has a chemical symbol of H2O, consisting of two, and not one, symbols, H and O.
Sulfate ion consists of a sulfide ion and four oxygen ions (SO4)2-. Hence, it does not fit.
Finally, potassium chloride has a chemical symbol of KCl. Consisting of two different chemical symbols, (K and Cl), it does not fit either.
Hope this helped!