What family has 4 valence electrons?

2) The pH of 1x10-1M (HNO3) solution is: A)1 B) 1.3 C)5 D)2

nikdorinn [45]

Concentration of H+ ions in HNO3 solution is 10⁻¹ which is equal to 0.1 M

$\bf \: pH \: = - log[{h}^{ + }]$

putting the value we get

$\sf \dashrightarrow \: pH \: = - log \: [ \frac{1}{10}] \\ \\ \sf \dashrightarrow \: pH \: = - log \: {10}^{ - 1} \\ \\ \sf \dashrightarrow \: pH \: = 1$

So, the required option is A) 1

8 0

2 years ago

5. At 20°C, the water autoionization constant, Kw, is 6.8 ´ 10–15. What is the H3O+ concentration in neutral water at this tempe

rjkz [21]

Explanation:

Let us assume that the concentration of [ $OH^{-}$ and $H^{+}$ is equal to x. Then expression for $K_{w}$ for the given reaction is as follows.

$K_{w} = [OH^{-}][H^{+}]$

$K_{w} = x^{2}$

$6.8 \times 10^{-15} = x^{2}$

Now, we will take square root on both the sides as follows.

$\sqrt{6.8 \times 10^{-15}} = \sqrt{x^{2}}$

$[H^{+}] = 8.2 \times 10^{-8}$ M

Thus, we can conclude that the $H_{3}O^{+}$ concentration in neutral water at this temperature is $8.2 \times 10^{-8}$ M.

8 0

3 years ago

Read 2 more answers

One of the emission lines that provides the green color in fireworks, which com s from barium salts, has a wavelength of 505nm.

PSYCHO15rus [73]

Explanation:

(a)

The relation between frequency and wavelength is shown below as:

$c=frequency\times Wavelength
$

c is the speed of light having value $3\times 10^8\ m/s$

Given, Wavelength = 505 nm

Also, 1 m = $10^{-9}$ nm

So,

Wavelength = $505\times 10^{-9}$ m

Thus, Frequency is:

$Frequency=\frac{c}{Wavelength}$

$Frequency=\frac{3\times 10^8}{505\times 10^{-9}}\ Hz$

$Frequency=5.94\times 10^{14}\ Hz$

(b)

Also, $E=\frac {h\times c}{\lambda}$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

c is the speed of light having value $3\times 10^8\ m/s$

So,

$E=\frac{6.626\times 10^{-34}\times 3\times 10^8}{505\times 10^{-9}}\ J$

$E=\frac{10^{-26}\times \:19.878}{10^{-9}\times \:505}\ J$

$E=3.94\times 10^{-19}\ J$

(c)

Electromagnetic spectrum is range of the frequencies and their respective wavelengths of the various type of the electromagnetic radiation.

In order of the increasing frequency and the photon energy and the decreasing wavelength the spectrum are:

Red , Orange, Yellow, Green, Blue, Indigo, Violet

Increasing wavelength is the opposite trend. Thus, The longest visible wavelength is red and the shortest is violet.

6 0

3 years ago

A balloon has a volume of 10,500 liters, and the temperature is 15°C. If the temperature were -25°C, what would the volume of th

harina [27]

Answer is: b) 9,042 L.
Ideal gas law: p·V = n·R·T.
p is the pressure of the gas.
V is the volume of the gas.
n is amount of substance.
R is universal gas constant.
T is temperature.
T₁ = 15°C = 288 K.
V₁ = 10,5 L.
T₂ = -25°C = 248 K.
V₂ = ?
V₁/T₁ = V₂/T₂
V₂ = 10,5 L · 248 K ÷ 288 K
V₂ = 9,042 L.

8 0

3 years ago

The combined gas law states that

seropon [69]

Answer:

Option B. PV = nRT.

Explanation:

From the above,

C = PV / T. (1)

But, C is directly proportional to n, where R is the gas constant i.e

C & n

C = nR

Substituting the value of C into equation (1), we have:

C = PV / T

nR = PV / T

Cross multiply to express in linear form

nRT = PV

Therefore,

PV = nRT

8 0

2 years ago