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3 years ago

Which of the following is a monatomic anion? a) NH4+ b) Fr+ c) SO42– d) F-

Chemistry

2 answers:

Y_Kistochka [10]3 years ago

8 0

I think that it's d) F- but I'm not sure.

spin [16.1K]3 years ago

4 0

Answer:

d) F⁻

Explanation:

An anion is an ion that has a net negative charge. Ions such as OH⁻, NO₃⁻ or Cl⁻ are anions.

Monatomic means that it is made of only one atom. Mono=one. Ions such as H⁺, Na⁺ or S²⁻ are monoatomic, whereas ions such as OH⁻, NH₄⁺ or CN⁻ are <u>polyatomic</u>.

With this information in mind, the option that is both monatomic and an anion is d), F⁻.

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All the elements of a family in the periodic table have what feature in common?a)they all have similar chemical properties.b)the

Vadim26 [7]

<span>Answer: D. They all have the same number of electrons in the electron cloud</span>

5 0

3 years ago

Read 2 more answers

What is the limiting reactant in a chemical reaction?

IgorC [24]

Answer:

D.) the reactants that runs out first

Explanation:

Limiting reactant is the reactant which is present in the smallest amount and thus limit the yield of product.

In any chemical reaction limiting reactant is identified by steps:

First we will calculate the number of moles of given amount of reactants.

Then we will find the number of moles of product by comparing with moles of reactant through balanced chemical equation.

Then we will identified the reactant which produced smaller amount of product.

It can be better understand by following problem.

Given data:

Mass of calcium carbonate = 25 g

Mass of hydrochloric acid = 13.0 g

Mass of calcium chloride produced = ?

Which is limiting reactant= ?

Chemical equation:

CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂

Number of moles of CaCO₃:

Number of moles of CaCO₃ = Mass /molar mass

Number of moles of CaCO₃= 25.0 g / 100.1 g/mol

Number of moles of CaCO₃ = 0.25 mol

Number of moles of HCl:

Number of moles of HCl = Mass /molar mass

Number of moles of HCl = 13.0 g / 36.5 g/mol

Number of moles of HCl = 0.36 mol

Now we will compare the moles of CaCl₂ with HCl and CaCO₃ .

CaCO₃ : CaCl₂

1 : 1

0.25 : 0.25

HCl : CaCl₂

2 : 1

0.36 : 1/2 × 0.36 = 0.18 mol

The number of moles of CaCl₂ produced by HCl are less it will be limiting reactant.

Mass of calcium chloride:

Mass of CaCl₂ = moles × molar mass

Mass of CaCl₂ =0.18 mol × 110.98 g/mol

Mass of CaCl₂ = 20 g

5 0

3 years ago

Knowing that the protease shows highest activity between pH 4-6, what could be the identity of the base residue acting as a in t

olga_2 [115]

hey there!:

A) Knowing theatre the protease is showing the highest activity at pH 4-6, implies that the amino acid that amino acid that it is acting in is an amino acid with a basic side chain. Therefore, the residues can be any one of the three basic amino acids being histidine, arginine or lysine , having basic side chains at neutral pH.

b) The mechanism of reaction of cysteine proteases is as follows:

First step in the reaction is the deprotonation of a thiol in the cysteine proteases's active site by an adjacent amino acid with a basic side chain, which might be a histidine residue. This is followed by a nucleophilic attack by the anionic sulfur of the deprotonated cysteine on the substrate carbonyl carbon.

Here, a part of the substrate is released with an amine terminus, restoring the His into a deprotonated form, thus forming a thioester intermediate, forming a link between the carboxy-terminal of the substrate and cysteine, resulting in thiol formation. Thus the name thiol proteases. The thioester bond is then hydrolyzed into a carboxylic acid moiety while again forming the free enzyme.

C) cysteine proteases have a pka of 8-9 but when they are deprotonated by a His residue, their pka would come down to 6-8, which would be their optimal pH for functioning. This is because there is a deprotonation of the thiol group , later restoring the HIS deprotonated form and then formation of a thioester bond. This thioester bond when hydrolysed will a carboxylate moeity , which is responsible for bringing the pH down towards a more acidic side.

d) at the optimal pH , the fraction of deprotonated cysteine and protonated B will be equal which will change with the change in pH.

Hope this helps!

8 0

3 years ago

Who discovered the principle that equal volumes of gases at the same temperature and pressure contain the same number of particl

Zarrin [17]

Answer:

Amedeo Avogadro

Explanation:

i think it may correct.

5 0

3 years ago

How does a dietitian help a patient

disa [49]

Answer:

the fourth option (D)

Explanation:

6 0

3 years ago