Is A B C or D I need help

Acetic acid is a weak acid with a pKa of 4.76. What is the concentration of acetate in a buffer solution of 0.2M at pH 4.9. Give

Ghella [55]

Answer:

$[base]=0.28M$

Explanation:

Hello,

In this case, by using the Henderson-Hasselbach equation one can compute the concentration of acetate, which acts as the base, as shown below:

$pH=pKa+log(\frac{[base]}{[acid]} )\\\\\frac{[base]}{[acid]}=10^{pH-pKa}\\\\\frac{[base]}{[acid]}=10^{4.9-4.76}\\\\\frac{[base]}{[acid]}=1.38\\\\$

$[base]=1.38[acid]=1.38*0.20M=0.28M$

Regards.

6 0

3 years ago

What is the specific heat of iron, if it requires 1120 J of heat energy to raise the

IRISSAK [1]

Answer:

Specific heat is defined as the amount of heat needed to raise the temperature by one degree celsius. Therefore, in 1 kg there are 100 grams so, 10 grams equal 0.01 Kg. Thus, calculate the specific heat value as follows. Thus, we can conclude that specific heat of the given metal is 0.5 .

Explanation:

4 0

2 years ago

Annoying user "Living under a bridge" its for a crossword

natulia [17]

I think the word might be a “troll”

3 0

3 years ago

Balance the following chemical

poizon [28]

Answer:

Explanation:

A chemical formula can be defined as a notation that is used to show which element and how many is contained in a chemical compound.

Also, in chemistry, the sum of charges of the anion and the cation of any ionic compound is always equal to zero.

A chemical equation is considered to be balanced when the amount of reactants on the left is equal to the amount of products on the right.

Therefore;

[2]FeBr3 + [3]Na2S → [1]Fe2S3 + [6]NaBr

In the above chemical equation, we will balance the reactants in the chemical equation with the smallest coefficients possible;

$2FeBr_{3} + 3Na_{3}S ----> Fe_{2}S{3} + 6NaBr$

Two (2) moles of Iron (III) Bromide reacts with two (2) moles of Sodium Sulfide to form Iron (III) Sulfide and Sodium Bromide.

4 0

2 years ago

1.20 x 10^22 molecules NaOH to gram

Trava [24]

Answer:

$\boxed {\boxed {\sf 0.797 \ g \ NaOH}}$

Explanation:

1. Convert Molecules to Moles

First, we must convert molecules to moles using Avogadro's Number: 6.022*10²³. This tells us the number of particles in 1 mole of a substance. In this case, the particles are molecules of sodium hydroxide.

$\frac {6.022*10^{23} \ molecules \ NaOH} {1 \ mol \ NaOH}}$

Multiply by the given number of molecules.

$1.20*10^{22} \ molecules \ NaOH *\frac {6.022*10^{23} \ molecules \ NaOH} {1 \ mol \ NaOH}}$

Flip the fraction so the molecules cancel out.

$1.20*10^{22} \ molecules \ NaOH *\frac {1 \ mol \ NaOH} {6.022*10^{23} \ molecules \ NaOH}}$

$1.20*10^{22} *\frac {1 \ mol \ NaOH} {6.022*10^{23}}}$

$\frac {1.20*10^{22} \ mol \ NaOH} {6.022*10^{23}}}$

$0.0199269345732 \ mol \ NaOH$

2. Convert Moles to Grams

Next, we convert moles to grams using the molar mass.

We must calculate the molar mass using the values on the Periodic Table. Look up each individual element.

Na: 22.9897693 g/mol
O: 15.999 g/mol
H: 1.008 g/mol

Since the formula has no subscripts, we can simply add the molar masses.

NaOH: 22.9897693+15.999+1.008=39.9967693 g/mol

Use this as a ratio.

$\frac {39.9967693 \ g \ NaOH }{1 \ mol \ NaOH}$

Multiply by the number of moles we calculated.

$0.0199269345732 \ mol \ NaOH*\frac {39.9967693 \ g \ NaOH }{1 \ mol \ NaOH}$

The moles of sodium hydroxide cancel.

$0.0199269345732 *\frac {39.9967693 \ g \ NaOH }{1}$

$0.0199269345732 *39.9967693 \ g \ NaOH$

$0.79701300498 \ g \ NaOH$

The original measurement of molecules has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place. The 0 tells us to leave the 7 in the hundredth place.

$0.797 \ g \ NaOH$

1.20*10²² molecules of sodium hydroxide is approximately 0.797 grams.

4 0

3 years ago