Which type of stoichiometric calculation does not require the use of the molar mass?

Which statement accurately describes the origin and expansion of the universe? As the universe continues to expand, it gradually

dimulka [17.4K]

The answer is; Cosmic background radiation is leftover thermal energy from the big bang.

Called the coming microwave background the weak radiation fills the universe more or less uniformly. This radiation is the fossil remnants of the postulated big band at the beginning of the universe. The photos produced at the time continue to travel through the universe growing fainter over time and have fallen in the microwave range of the electromagnetic spectrum now.

5 0

3 years ago

Read 2 more answers

I need help with everything

maria [59]

For the hypothesis put what you think will happen

6 0

3 years ago

Calculate [H3O+] and [OH−] for each of the following solutions at 25 ∘C given the pH. pH= 8.74, pH= 11.38, pH= 2.81

Gnom [1K]

Answer:

Explanation:

Given parameters;

pH = 8.74

pH = 11.38

pH = 2.81

Unknown:

concentration of hydrogen ion and hydroxyl ion for each solution = ?

Solution

The pH of any solution is a convenient scale for measuring the hydrogen ion concentration of any solution.

It is graduated from 1 to 14

pH = -log[H₃O⁺]

pOH = -log[OH⁻]

pH + pOH = 14

Now let us solve;

pH = 8.74

since pH = -log[H₃O⁺]

8.74 = -log[H₃O⁺]

[H₃O⁺] = 10⁻ $^{8.74}$

[H₃O⁺] = 1.82 x 10⁻⁹mol dm³

pH + pOH = 14

pOH = 14 - 8.74

pOH = 5.26

pOH = -log[OH⁻]

5.26 = -log[OH⁻]

[OH⁻] = 10 $^{-5.26}$

[OH⁻] = 5.5 x 10⁻⁶mol dm³

2. pH = 11.38

since pH = -log[H₃O⁺]

11.38 = -log[H₃O⁺]

[H₃O⁺] = 10⁻ $^{11.38}$

[H₃O⁺] = 4.17 x 10⁻¹² mol dm³

pH + pOH = 14

pOH = 14 - 11.38

pOH = 2.62

pOH = -log[OH⁻]

2.62 = -log[OH⁻]

[OH⁻] = 10 $^{-2.62}$

[OH⁻] =2.4 x 10⁻³mol dm³

3. pH = 2.81

since pH = -log[H₃O⁺]

2.81 = -log[H₃O⁺]

[H₃O⁺] = 10⁻ $^{2.81}$

[H₃O⁺] = 1.55 x 10⁻³ mol dm³

pH + pOH = 14

pOH = 14 - 2.81

pOH = 11.19

pOH = -log[OH⁻]

11.19 = -log[OH⁻]

[OH⁻] = 10 $^{-11.19}$

[OH⁻] =6.46 x 10⁻¹²mol dm³

5 0

3 years ago

What is the volume of 1g of ice in cm3?

Amanda [17]

Answer:

What is the volume of 1g of ice in cm3?

Explanation:

3 0

3 years ago

How many electrons does carbon lack in its outer shell? biochemistry

tekilochka [14]

A neutral carbon doesn't lack any electrons. It has exactly the same number of electrons as it has neutrons.
However, it has four electrons in its outer shell in comparison with eight electrons for a noble gas.
In that sense, it needs four electrons to complete its second shell.<span />

7 0

3 years ago