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3 years ago

A change in matter that produces one or more new substances is a(n)

1 answer:

6 0

You could use another word for change can be variable witch means change and if you times the one two more times then you would get four because two time two would be four and times the one would be four.

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The volume of a given mass of agas is 360cm cubic at 50 degrees and 700 milimetres Hg .find it's volume at s.t.p

saveliy_v [14]

Answer:

V₂ =279.9 cm³

Explanation:

Given data:

Initial volume = 360 cm³

Initial temperature = 50°C

Initial pressure = 700 mmHg

Final volume = ?

Final temperature = 273 k

Final pressure = 1 atm

Solution:

According to general gas equation:

P₁V₁/T₁ = P₂V₂/T₂

Solution:

We will convert the mmHg to atm.

700/760 = 0.92 atm

and °C to kelvin.

50+273 = 323 K

P₁V₁/T₁ = P₂V₂/T₂

V₂ = P₁V₁ T₂/ T₁ P₂

V₂ = 0.92 atm × 360 cm³ × 273 K / 323 K ×1 atm

V₂ = 290417.6 atm .cm³. K / 323 k. atm

V₂ =279.9 cm³

8 0

3 years ago

An aqueous solution of glucose has molality of 6.81 and a density of 1.2 g/ml what is the molarity of glucose in the solution

andriy [413]

Answer:

the molarity is 3.68 moles/L

Explanation:

the molality of the solution of sucrose is

m= moles of glucose / Kg of solvent (water)= 6.81 ,

since the molecular weight of glucose is 180.156 gr/mole , then per each kilogram of solvent there is

6.81 moles*180.156 gr/mole + 1000 gr of water = 2226.86 gr of solution

from the density

volume of solution = mass of solution/density = 2286.86 gr / 1.2 gr/ml = 1855.71 ml

therefore there is 1000 gr of water in 1855.71 ml

then the molarity M is

M= moles of glucose / L of solution = (moles of glucose / Kg of solvent) * (Kg of solvent/L of solution) = 6.81 moles/Kg * 1Kg/1.85 L = 3.68 moles/L

M= 3.68 moles/L

Note:

- Would be wrong in this case to assume density of water = 1 Kg/L since the solution is heavily concentrated in glucose and therefore the density of water deviates from its pure value.

3 0

3 years ago

How many electrons would be in a calcium cation with a positive 2 charge?

kondor19780726 [428]

Number of electrons in a Ca²⁺ = 18

<h3>Further explanation </h3>

In an atom there are levels of energy in the shell and sub shell

This energy level is expressed in the form of electron configurations.

Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f. The maximum number of electrons for each sub shell is

• s: 2 electrons

• p: 6 electrons

• d: 10 electrons and

• f: 14 electrons

Charging electrons in the sub shell uses the following sequence:

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.

The element Ca has an atomic number of 20, so the number of electrons and protons (in neutral atoms) is also 20

Electron configuration of Ca : 1s², 2s², 2p⁶, 3s², 3p⁶, 4s² ⇒[Ar] 4s²

When Ca releases 2 electrons to gain stability (forming Ca²⁺ cations), the number of electrons becomes:

$\tt 20-2 = 18$

and the electron configuration (Ca²⁺ ) becomes:

1s², 2s², 2p⁶, 3s², 3p⁶

6 0

2 years ago

Anatom that has lewer neutrons than protons and more electrons than protons is

Ludmilka [50]

Answer:

a negative ion, and an isotope.

Explanation:

The perfect atom consists of an equal balance in all 3. If the neutrons are not even with the protons, it is an isotope since it is like another version of the so called (but not actually) 'perfect' atom. If there is more electrons, the charge is negative, making it an ion.

8 0

3 years ago

The electron in a hydrogen atom can undergo a transition from n = 4 to n = 3, emitting a photon with energy 1.06 × 10 –19J. Use

konstantin123 [22]

Answer:

Wavelength (λ) = 1.875 × 10⁻⁶ m

Explanation:

Given:

Energy (e) = 1.06 × 10⁻¹⁹ J

Find:

Wavelength (λ) = ?

Computation:

e = hc / λ

λ = hc / e

where c = 3 × 10⁸

Planck's constant (h) = 6.625 × 10⁻³⁴

So,

Wavelength (λ) = (6.625 × 10⁻³⁴)(3 × 10⁸) / (1.06 × 10⁻¹⁹)

1. Wavelength (λ) = 1.875 × 10⁻⁶ m

2. Given n = 4 to n = 3 both are integer not fraction so, electron is quantize

5 0

2 years ago