All categories

3 years ago

A solution that is 0.20 m in hcho2 and 0.15 m in nacho2 find ph

1 answer:

5 0

We are given
0.2 M HCHO2 which is formic acid, a weak acid
and
0.15 M NaCHO2 which is a salt which can be formed by reacting HCHO2 and NaOH

The mixture of the two results to a basic buffer solution
To get the pH of a base buffer, we use the formula
pH = 14 - pOH = 14 - (pKa - log [salt]/[base])

We need the pKa of HCO2
From, literature, pKa = 1.77 x 10^-4
Substituting into the equation
pH = 14 - (1.77 x 10^-4 - log 0.15/0.2)
pH = 13.87

So, the pH of the buffer solution is 13.87
A pH of greater than 7 indicates that the solution is basic and a pH close to 14 indicates high alkalinity. This is due to the buffering effect of the salt on the base.

You might be interested in

Balance the chemichal equation: NH3+CuO➡️Cu+N2+H2O

Gala2k [10]

2NH3+3CuO➡️3Cu+N2+3H2O

4 0

2 years ago

Which two elements are in the same period?A. hydrogen (H) and neon (Ne)B. tin (Sn) and antimony (Sb)C. fluorine (F) and chlorine

ArbitrLikvidat [17]

Answer:

C. fluorine (F) and chlorine (Cl)

D. arsenic (As) and antimony (Sb)

Explanation:

In the periodic table , all the elements are arranged according to the atomic number ,

and the elements are placed in groups and periods ,

The elements with similar chemical and physical properties are placed in a common group .

The elements present in the same group have the same number of valence electrons in the valence shell .

Hence , from the given options ,

fluorine (F) and chlorine (Cl) belongs to group 17 with 7 valence electrons in the outermost shell .

arsenic (As) and antimony (Sb) belong to group 15 with 3 valence electrons in the outermost shell .

8 0

2 years ago

iron is made by a reduction of iron oxide with carbon monoxide. Fe2O3+3CO-2Fe+3CO2. Calculate the mass of iron that can be forme

lyudmila [28]

Answer:

Mass = 88.12 g

Explanation:

Given data:

Mass of iron oxide = 126 g

Mass of iron formed = ?

Solution:

Chemical equation:

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Number of moles of iron oxide:

Number of moles = mass/molar mass

Number of moles = 126 g/ 159.69 g/mol

Number of moles = 0.789 mol

Now we will compare the moles of iron with iron oxide.

Fe₂O₃ : Fe

1 : 2

0.789 : 2/1×0.789 = 1.578 mol

Mass of iron:

Mass = number of moles ×molar mass

Mass = 1.578 mol × 55.84 g/mol

Mass = 88.12 g

4 0

2 years ago

Filtration and dialysis are techniques that rely on differences in particle size to separate mixture components. True False

soldier1979 [14.2K]

This is true. Think about when you make pasta. The colander acts as a filter and doesn't let the past a through but allows the extra water to escape because the pasta is too big to fit.

3 0

2 years ago

Read 2 more answers

Completion

Snowcat [4.5K]

Answer:

Compress
Fixed
Melts
Melting Point
Freezing Point
High
Crystalline
Lattice
Unit cell
Amorphous solids

Explanation:

Solids tend to be dense and difficult to compress.

They do not flow or take the shape of their containers, like liquids do, because the particles in solids vibrate around fixed points.

When a solid is heated until its particles vibrate so rapidly that they are no longer held in fixed positions, the solid melts.

Melting point is the temperature at which a solid changes to a liquid. The melting and freezing point of a substance are at the same temperature.

In general, ionic solids tend to have relatively high melting points, while molecular solids tend to have relatively low melting points.

Most solids are crystalline

The particles are arranged in a pattern known as a crystal lattice

The smallest subunit of a crystal lattice is the unit cell

Some solids lack an ordered internal structure and are called amorphous solids.

7 0

2 years ago