All categories

2 years ago

The pH of a solution with a hydrogen-ion concentration of 4.90 x 10-'Mi

Chemistry

1 answer:

GrogVix [38]2 years ago

5 0

Answer:

pH < 7; pH = 7; pH > 7

Explanation:

when dealing with an acidic base, you have the formula for [H3O+] > [OH-] which yields a pH < 7.

when you have a neutral base, the reactive ion concentration would be [H3O^+] = [OH^-] which yields a pH = 7.

finally, when dealing with a basic classification, the formula would be [H3O^+] < [OH^-] yields a pH > 7.

You might be interested in

In IR spectroscopy, we normally talk about "frequencies" when in reality we are referring to wavenumbers. What is the mathematic

Svetach [21]

Answer:

Here's what I get.

Explanation:

(b) Wavenumber and wavelength

The wavenumber is the distance over which a cycle repeats, that is, it is the number of waves in a unit distance.

$\bar \nu = \dfrac{1}{\lambda}$

Thus, if λ = 3 µm,

$\bar \nu = \dfrac{1}{3 \times 10^{-6} \text{ m}}= 3.3 \times 10^{5}\text{ m}^{-1} = \textbf{3300 cm}^{-1}$

(a) Wavenumber and frequency

Since

λ = c/f and 1/λ = f/c

the relation between wavenumber and frequency is

$\bar \nu = \mathbf{\dfrac{f}{c}}$

Thus, if f = 90 THz

$\bar \nu = \dfrac{90 \times 10^{12} \text{ s}^{-1}}{3 \times 10^{8} \text{ m$\cdot$ s}^{-1}}= 3 \times 10^{5} \text{ m}^{-1} = \textbf{3000 cm}^{-1}$

(c) Units

(i) Frequency

The units are s⁻¹ or Hz.

(ii) Wavelength

The SI base unit is metres, but infrared wavelengths are usually measured in micrometres (roughly 2.5 µm to 20 µm).

(iii) Wavenumber

The SI base unit is m⁻¹, but infrared wavenumbers are usually measured in cm⁻¹ (roughly 4000 cm⁻¹ to 500 cm⁻¹).

8 0

3 years ago

What are two types of cold air masses that influence the weather in North America? Name them and describe their humidity.

I am Lyosha [343]

Tropical or warm air masses form in the tropics and have low air pressure.

polar or cold air masses form north of 50 degrees north latitude and south of 50 degrees south latitude

8 0

2 years ago

If a sample containing 18.1 g of NH3 is reacted with 90.4 g of

USPshnik [31]

Answer:

3.64g

Explanation:

Given parameters:

Mass of NH₃ = 18.1g

Mass of Cu₂O = 90.4g

Unknown:

Limiting reactant = ?

Mass of N₂ formed = ?

Solution:

The reaction equation is given as:

Cu₂O + 2NH₃ → 6Cu + N₂ + 3H₂O

The limiting reactant is the one in short supply in the reaction. Let us find the number of moles of the given species;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of Cu₂O = 2(63.6) + 16 = 143.2g/mol

Molar mass of NH₃ = 14 + 3(1) = 17g/mol

Number of moles of Cu₂O = $\frac{18.1}{143.2}$ = 0.13moles

Number of moles of NH₃ = $\frac{90.4}{17}$ = 5.32moles

From this reaction;

1 mole of Cu₂O combines with 2 mole of NH₃

So 0.13moles of Cu₂O will combine with 0.13 x 2 mole of NH₃

= 0.26moles of NH₃

Therefore, Cu₂O is the limiting reactant. Ammonia is in excess;

Mass of N₂;

Mass = number of moles x molar mass

1 mole of Cu₂O will produce 1 mole of N₂

0.13 mole of Cu₂O will produce 0.13 mole of N₂

Mass = 0.13 x (2 x 14) = 3.64g

5 0

3 years ago

Hard water often contains dissolved Ca2+ and Mg2+ ions. One way to soften water is to add phosphates. The phosphate ion forms in

katrin2010 [14]

Answer:

$22.4269$ grams of sodium phosphate must be added to 1.4 L of this solution to completely eliminate the hard water ions

Explanation:

We will first write the balanced equation for this scenario

3 CaCl2 + 2 Na3PO4 ----> 6 NaCl + Ca3 (PO4)2

3 Mg(NO3)2 + 2 Na3PO4 -----> 6 NaNO3 + Mg3 (PO4)2

The ratio here for both calcium chloride and magnesium nitrate is $3:2$

The number of moles of each compound is equal to

$0.054 * 1.4 = 0.0756\\0.093* 1.4 = 0.1302$

Using the mole ratio of 3:2, convert each to moles of sodium phosphate.

$0.0756$ mole of CaCl2 is equal to $0.05\\$ Na3PO4

$0.1302$ mole of CaCl2 is equal to $0.0868$ Na3PO4

Converting moles of sodium phosphate to grams of sodium phosphate we get

$(0.05 +0.0868) * 163.94$ g/mol

$22.4269$ grams of sodium phosphate must be added to 1.4 L of this solution to completely eliminate the hard water ions

8 0

3 years ago

Please help me

klio [65]

Answer:

Vascular plants are successful due to better transportation for water, nutrients and reproduction.

Explanation:

I got it right at school and hope this helps you learn to STUDY.jk

6 0

3 years ago