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exis [7]
2 years ago
15

20. When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by nuclear fusion, the cor

e becomes unstable and contracts. The outer shellof the star, which is still mostly hydrogen, starts to expand. At this phase the star is called a _____.
a.White dwarf
b.Red dwarf
c.Red Giant
d.Black hole
Chemistry
1 answer:
Triss [41]2 years ago
5 0

Answer:

b

Explanation:

i seached it up

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Write the balanced chemical equation between H2SO4H2SO4 and KOHKOH in aqueous solution. This is called a neutralization reaction
const2013 [10]

Answer:

0.185M sulfuric acid

Explanation:

Based on the reaction:

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

<em>1 mole of sulfuric acid reacts with 2 moles of KOH</em>

Initial moles of H₂SO₄ and KOH are:

H₂SO₄: 0.750L ₓ (0.470mol / L) = <em>0.3525 moles of H₂SO₄</em>

KOH: 0.700L ₓ (0.240mol / L) = <em>0.168 moles of KOH</em>

The moles of sulfuric acis that react with KOH are:

0.168mol KOH ₓ (1 mole H₂SO₄ / 2 moles KOH) = 0.0840 moles of sulfuric acid.

Thus, moles that remain are:

0.3525moles - 0.0840 moles = <em>0.2685 moles of sulfuric acid remains</em>

As total volume is 0.700L + 0.750L = 1.450L, concentration is:

0.2685mol / 1.450L = <em>0.185M sulfuric acid</em>

8 0
2 years ago
In the Bohr model of the hydrogen atom, the energy required to excite an electron from n = 2 to n = 3 is _______________ the ene
yawa3891 [41]

Answer:

greater than

Explanation:

4 0
3 years ago
Use the following equation to answer the questions below.
sertanlavr [38]

Answer:

Explanation:

Here is ur answer what you wanna do first is calculate the first and second numbers and letters this should be ur answer = -394 + 2 x (-242) - (-75) + 2 x 0 = -803 kJ/mol

4 0
2 years ago
Calculate the mass percent of Cl in Freon -112 (C2 Cl4 F2), a CFC refrigerant
Karolina [17]

Answer:

The answer to your question is:  69.6 %

Explanation:

Freon -112 (C₂Cl₄F₂)

MW = (12 x 2) + (35.5 x 4) + (19 x 2)

      = 24 + 142 + 38

      = 204 g

                       204 g of C₂Cl₄F₂  -----------------  100%

                       142 g                     -----------------   x

                      x = (142 x 100 ) / 204

                      x = 69.6 %

5 0
3 years ago
Read 2 more answers
How many of sodium (Na) are needed to make 4.5 liters of a 1.5mol/L of Na solution?​
Salsk061 [2.6K]

Answer:

Explanation:

First you will find the mole from the molarity and then the desired mass from the mole.

5 0
2 years ago
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