The observed brightness of a star depends on which factors?

A sample of nitrogen gas has the temperature drop from 250.°c to 150.°c at constant pressure. what is the final volume if the in

Leviafan [203]

Charles law gives the relationship between temperature of gas and volume of gas.
It states that for a fixed amount of gas, temperature is directly proportional to volume of gas.
V / T = k
where V- volume , T - temperature and k - constant
$\frac{V1}{T1} = \frac{V2}{T2}$
parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation.
T1 = 250 °C + 273 = 523 K
T2 = 150 °C + 273 = 423 K
Substituting the values in the equation,

$\frac{310 mL}{523 K} = \frac{V}{423K}$
V = 251 mL
the new volume is 251 mL

6 0

3 years ago

How many moles of Cu do you need to react with 12 moles of O2? 2Cu(s) + O2(g) 2CuO(s)

zzz [600]

Answer:

24 mol Cu

General Formulas and Concepts:

Chemistry

Stoichiometry

Explanation:

Step 1: Define

RxN: 2Cu (s) + O₂ (g) → 2CuO (s)

Given: 12 moles O₂

Step 2: Stoichiometry

$12 \ mol \ O_2(\frac{2 \ mol \ Cu}{1 \ mol \ O_2} )$ = 24 mol Cu

Step 3: Check

We are given 2 sig figs.

Our final answer is in 2 sig figs, so no need to round.

3 0

2 years ago

All single-displacement reactions can be classified as another type of reaction as well. What type of reaction is that?

user100 [1]

combustion because one atom in wrong place will make it combust

8 0

3 years ago

Read 2 more answers

Give the formula for an ionic compound formed from each pair of ions

Vera_Pavlovna [14]

Please, find the complete question in the picture attached.

Answer:

1. Na₂O

2. AlF₃

3. MgO

4. Ca₃P₂

Explanation:

1. Na⁺ and O²⁻

An ionic compound will be formed when two ions of opposite charge attract each other.

The positive ion is called cation and the negative ion is called anion.

Thus, every ionic compound has a cation and an anion electrostatically bonded.

The ions must combine in a proportion that genders a neutral compound: so you must have as many cations as negative charge has one anion and as many anions as positive charge has one cation.

This is, if the cation has charge +x, there will be x anions, and if the anion has charge -y, there will be y cations.

Simbolically:

$Cation:A^{+x}\\ \\ Anion:B^{-y}\\ \\ Compound:A_yB_x$

As you see, the subscripts for each element in the chemical formula are obtained by the exchage of the charges of the ions.

Then, for Na⁺ and O²⁻, the subscript for Na will be 2 and the subscript for O will be 1; and the formula of the ionic compound formed by this pair ot ions is:

Na₂O

2. Al³⁺ and F⁻

The subscript of Al will be 1 (because the F ion has charge 1-, and the subscript of F will be 3 (because the Al ion has charge +3).

Thus the ionic compound formed by this pair of ions is:

AlF₃

3. Mg²⁺ and S²⁻

The charge 2+ from Mg atom wil become the subscript 2 of S atom, and the charge 2- will become the subscript 2 of Mg atom:

That results in the formula: Mg₂S₂

Except for some special compounds, the chemical formula is simplified, dividing by the least common denominator. In this case, that means that the two 2 subscripts are simplified to 1, and the final chemical formula for the ionic compound formed by this pair of ions is:

MgO

4. Ca²⁺ and P³⁻

The charge 2+ from Ca will become subscript 2 for P and the charge 3- whill become subscript 3 for Ca.

Hence, the ionic compound formed by these two ions is:

Ca₃P₂

7 0

2 years ago

PLZ HELP!!!

HACTEHA [7]

Answer:

Humans have 23 pairs of chromosomes.

A trisomy is a chromosomal condition characterised by an additional chromosome.

A person with a trisomy has 47 chromosomes instead of 46.

Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy.

Explanation:

6 0

2 years ago