Describe the physical and chemical changes that take place during digestion

A sample of table sugar (sucrose c12h22o11) has a mass of 3.115 g

attashe74 [19]

Hey there:

a) atomic mass:

Carbon =12.0107 g/mol

Hydrogen = 1.00794 g/mol

Oxygen = 15.9994 g/mol

Therefore:

C12H22O11 =

12 * 12.0107 + 1 * 1.00794 + 16 * 15.9994 => 342.29648 g/mol

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b) number of moles:

n = m / mm

n = 3.115 / 342.29648

n = 0.0091 moles

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hope this helps!

6 0

3 years ago

Complete the acid–base equation for the dissolution of the following compound into liquid HF solvent. The relevant pKa values ar

LenKa [72]

Answer:

The balanced chemical equation: NH₃ + 2 HF → NH₄⁺ + HF₂⁻

Explanation:

According to the Brønsted–Lowry acid–base theory, the acid- base reaction is a type of chemical reaction between the acid and base to give a conjugate acid and a conjugate base.

In this reaction, a Brønsted–Lowry acid loses a proton to form a conjugate base. Whereas, a Brønsted–Lowry base accepts a proton to form a conjugate acid.

Acid + Base ⇌ Conjugate Base + Conjugate Acid

The acid dissociation constant (Kₐ) signifies the acidic strength of a chemical species.

∵ pKₐ = - log Kₐ

Thus for a strong acid, Kₐ value is large and pKₐ value is small.

pKₐ (HF) = 3.2 → strong acid

pKₐ (NH₃) = 38 → weak acid

The chemical reaction involved in the dissolution process:

NH₃ + 2 HF → NH₄⁺ + HF₂⁻

In this acid-base reaction, the acid HF reacts with NH₃ base to give the conjugate base HF₂⁻ and conjugate acid NH₄⁺.

HF (acid) donates a proton to form the conjugate base, HF₂⁻ ion. NH₃ (base) accepts a proton to form the conjugate acid.

7 0

3 years ago

Cite two important quantum-mechanical concepts associated with the Bohr model of the atom.(b) Cite two important additional refi

Alenkinab [10]

Answer: Bohr postulated that electronic energy levels are quantized. Secondly, a photon of light of a particular frequency is emitted when electrons move from a higher to a lower energy levels.

Explanation:

The Bohr model of the atom is the immediate predecessor of the wave mechanical model of the atom. The wave mechanical model refined the Bohr's model by treating the electron as a wave having a wave function psi. The wave function describes the identity of the electron. From Heisenberg uncertainty principle, the position of a particle cannot be accurately and precisely measured. Hence the wave mechanical model added that electrons are not localized in orbits according to Bohr's model but the integral of psi squared dx gives the probability of finding the electron within a given space.

8 0

3 years ago

Read 2 more answers

Complete and balance the following redox equation using the set of smallest whole– number coefficients. Now sum the coefficients

Elena L [17]

Answer : The balanced chemical equation in a acidic solution is,

$BrO_3^-(aq)+6H^+(aq)+3Sb^{3+}(aq)\rightarrow Br^-(aq)+3H_2O(l)+3Sb^{5+}(aq)$

The sum of the coefficients is, 17

Explanation :

Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.

Oxidation reaction : It is defined as the reaction in which a substance looses its electrons. In this, oxidation state of an element increases. Or we can say that in oxidation, the loss of electrons takes place.

Reduction reaction : It is defined as the reaction in which a substance gains electrons. In this, oxidation state of an element decreases. Or we can say that in reduction, the gain of electrons takes place.

Rules for the balanced chemical equation in acidic solution are :

First we have to write into the two half-reactions.

Now balance the main atoms in the reaction.

Now balance the hydrogen and oxygen atoms on both the sides of the reaction.

If the oxygen atoms are not balanced on both the sides then adding water molecules at that side where the less number of oxygen are present.

If the hydrogen atoms are not balanced on both the sides then adding hydrogen ion $(H^+)$ at that side where the less number of hydrogen are present.

Now balance the charge.

The given chemical reaction is,

$BrO_3^-(aq)+Sb^{3+}(aq)\rightarrow Br^-(aq)+Sb^{5+}(aq)$

The oxidation-reduction half reaction will be :

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-\rightarrow Br^-$

First balance the main element in the reaction.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-\rightarrow Br^-$

Now balance oxygen atom on both side.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-\rightarrow Br^-+3H_2O$

Now balance hydrogen atom on both side.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}$

Reduction : $BrO_3^-+6H^+\rightarrow Br^-+3H_2O$

Now balance the charge.

Oxidation : $Sb^{3+}\rightarrow Sb^{5+}+2e^-$

Reduction : $BrO_3^-+6H^++6e^-\rightarrow Br^-+3H_2O$

The charges are not balanced. Now multiplying oxidation reaction by 3 and then adding both equation, we get the balanced redox reaction.

Oxidation : $3Sb^{3+}\rightarrow 3Sb^{5+}+6e^-$

Reduction : $BrO_3^-+6H^++6e^-\rightarrow Br^-+3H_2O$

The balanced chemical equation in acidic medium will be,

$BrO_3^-(aq)+6H^+(aq)+3Sb^{3+}(aq)\rightarrow Br^-(aq)+3H_2O(l)+3Sb^{5+}(aq)$

The sum of the coefficients = 1 + 6 + 3 + 1 + 3 + 3

The sum of the coefficients = 17

7 0

3 years ago

What must take place for copper metal to be oxidized?

Oxana [17]

The copper would go under oxidation since it will be losing two electrons. Copper starts out with an oxidation number of zero, but in order to balance the compound of CuO with the Oxygen having an oxidation number of -2, a positive 2 is required

6 0

3 years ago