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3 years ago

What point does the ammonium ions act as a buffer solution? Please this is driving me insane.

Chemistry

1 answer:

Shalnov [3]3 years ago

7 0

Answer:

Explanation:The buffer is a mixture of ammonia (NH3) and ammonium (NH4+). ... Since ammonia (NH3) is a weak base, it will have a pH above 7 and since ammonium (NH4+) is a weak acid, it will have a pH below 7. Ammonia (NH3) is a weak base and ammonium (NH4+) is a weak acid. Ammonia (NH3) is the conjugate base of ammonium (NH4+).

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Sodium hydrogen carbonate , also known as sodium bicarbonate or "baking soda", can be used to relieve acid indigestion. Acid ind

Yanka [14]

Answer:

The mass of NaHCO3 that she would need to ingest to neutralize this much HCl is 1.512g

Explanation:

The question can be better presented as follows:

Sodium hydrogen carbonate NaHCO3, also known as sodium bicarbonate or "baking soda", can be used to relieve acid indigestion. Acid indigestion is the burning sensation you get in your stomach when it contains too much hydrochloric acid HCl, which the stomach secretes to help digest food. Drinking a glass of water containing dissolved NaHCO3 neutralizes excess HCl through this reaction: HCl(aq)+NaHCO3(aq)→NaCl(aq)+H2O(l)+CO2(g)

The CO2 gas produced is what makes you burp after drinking the solution. Suppose the fluid in the stomach of a woman suffering from indigestion can be considered to be 200.mL of a 0.089M HCl solution. What mass of NaHCO3 would she need to ingest to neutralize this much HCl? Be sure your answer has the correct number of significant digits.

SOLUTION

Given:

Volume of HCl = 200ml = 0.200L

Molarity of the HCl =>0.089M

The number of mole of HCl can be calculated using C=n/V

Therefore n = CxV = 0.089 × 0.2

=0.018 moles

Equation for the reaction:

HCl(aq)+NaHCO3(aq)→NaCl(aq)+H2O(l)+CO2(g)

From the equation, 1mole of HCl required 1mole of NaHCO3 for neutralization; therefore 0.018 moles of HCl will require 0.018 moles of NaHCO3.

But molar mass of NaHCO3 = 23+1+12+(16×3) = 84

Finally using number of moles = mass/molar mass

Therefore mass = 0.018 × 84

= 1.512g

8 0

3 years ago

How to draw Hess' Cycle for this question ?

NISA [10]

Answer : The standard enthalpy of formation of ethylene is, 51.8 kJ/mole

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The formation reaction of $C_2H_4$ will be,

$2C(s)+2H_2(g)\rightarrow C_2H_4(g)$ $\Delta H_{formation}=?$

The intermediate balanced chemical reaction will be,

(1) $C_2H_4(g)+3O_2(g)\rightarrow 2CO_2(g)+2H_2O(l)$ $\Delta H_1=-1411kJ/mole$

(2) $C(s)+O_2(g)\rightarrow CO_2(g)$ $\Delta H_2=-393.7kJ/mole$

(3) $H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l)$ $\Delta H_3=-285.9kJ/mole$

Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equations, we get :

(1) $2CO_2(g)+2H_2O(l)\rightarrow C_2H_4(g)+3O_2(g)$ $\Delta H_1=+1411kJ/mole$

(2) $2C(s)+2O_2(g)\rightarrow 2CO_2(g)$ $\Delta H_2=2\times (-393.7kJ/mole)=-787.4kJ/mole$

(3) $2H_2(g)+2O_2(g)\rightarrow 2H_2O(l)$ $\Delta H_3=2\times (-285.9kJ/mole)=-571.8kJ/mole$

The expression for enthalpy of formation of $C_2H_4$ will be,

$\Delta H_{formation}=\Delta H_1+\Delta H_2+\Delta H_3$

$\Delta H=(+1411kJ/mole)+(-787.4kJ/mole)+(-571.8kJ/mole)$

$\Delta H=51.8kJ/mole$

Therefore, the standard enthalpy of formation of ethylene is, 51.8 kJ/mole

7 0

3 years ago

The following is a procedure that was theoretically performed by a student. Read through the procedure and answer the questions

yKpoI14uk [10]

Answer:

CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)

Explanation:

We have the reactants as calcium chloride and potassium carbonate. Recall that we are expecting that the reaction will yield a precipitate. We must keep that in mind as we seek to write its balanced chemical reaction equation.

So we now have;

CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)

Recall that the rule of balancing chemical reaction equation states that the number of atoms of each element on the right side of the reaction equation must be the same as the number of atoms of the same element on the left hand side of the reaction equation.

6 0

3 years ago

Revolution- is the orbiting of an object around another object... so what can i put as my example of revolution?

REY [17]

Answer:

The earth circling the sun

5 0

3 years ago

Please help with this, i don't really get how to do this

LuckyWell [14K]

#4 and #5:
To find pH given concentration of H+ or H30+
pH = - log (H+ or H30+ M)

To find pH given concentration of OH-
Since you already found the pH for this (in #4), you subtract #4's answer from 14.
14 - (pH) = pOH

8 0

3 years ago