Which types of changes must follow the law of conservation of mass?
Both physical and chemical changes
Neither physical nor chemical changes
Only physical changes
Only chemical changes

The given question is incomplete. The complete question is:

How much heat is produced when 24.8 g of [tex]CH_4[/tex] is burned in excess oxygen gas

Given: [tex]CH _4 +2O_2\rightarrow CO_2+2H_2O[/tex]  ΔH= −802 kJ.

Answer: 1243.1 kJ

Explanation:

Heat of combustion is the amount of heat released on complete combustion of 1 mole of substance.

Given :

Amount of heat released on combustion of  1 mole of methane = 802 kJ kJ/mol

According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

1 mole of [tex]CH_4[/tex] weighs = 16 g  

Thus we can say:  

16 g of [tex]CH_4[/tex] on combustion releases heat = 802 kJ

Thus 24.8 g of [tex]CH_4[/tex] on combustion releases =[tex]\frac{802}{16}\times 24.8=1243.1kJ[/tex]

Thus heat released when 24.8 g of methane is burned in excess oxygen gas is 1243.1 kJ

Answer:82.7% C and 17.3% H

Explanation:

C4 = 12.0107g/mol x 4 = 48.0428 g/mol

H10 = 1.00794 g/mol x 10 = 10.0794 g/mol

Molar Mass of Butane, C4H10 =  48.0428 g/mol + 10.0794 g/mol= 58.1222 g/mol

percent composition of Carbon is  = ( mass of carbon contained in butane / molar mass of Butane) x 100

=(48.0428 /58.1222) x 100% = 0.8265 x 100

=82.65% =82.7% of Carbon.

Percent composition of Hydrogen  = (mass of Hydrogen contained in Butane / molar mass of Butane )x 100  

( 10.0794/58.122 ) x 100% =0.1734 x 100

= 17.3% OF Hydrogen.

Answer:

C- 82.7% C and 17.3% H

Explanation:

I took the Quiz

Br- + 2MnO4- + 2H+ → BrO3- + 2MnO2 + H2O

Given

MnO4- + Br- = MnO2 + BrO3-

Required

The half-reaction

Solution

In acidic conditions :

1. Add the coefficient

2. Equalization O atoms (add H₂O) on the O-deficient side.  

3. Equalization H atoms (add H⁺ ) on the H -deficient side.  .  

4. Equalization of charge (add electrons (e) )

5. Equalizing the number of electrons and then adding the two half -reactions together

Oxidation : Br- → BrO3-  

Reduction : MnO4- → MnO2

Br- + 3H2O → BrO3-  

MnO4- → MnO2 + 2H2O

Br- + 3H2O → BrO3- + 6H+  

MnO4- + 4H+ → MnO2 + 2H2O

Br- + 3H2O → BrO3- + 6H+ + 6e-         x1

MnO4- + 4H+ + 3e- → MnO2 + 2H2O x2

Br- + 3H2O → BrO3- + 6H+ + 6e-  

2MnO4- + 8H+ + 6e- → 2MnO2 + 4H2O

Br- + 2MnO4- + 3H2O + 8H+ + 6e- → BrO3- + 2MnO2 + 6H+ + 4H2O + 6e-

Br- + 2MnO4- + 2H+ → BrO3- + 2MnO2 + H2O

Answer:

the object should be displaced on which the force is applied

Explanation:

HOPE IT HELPS YOU

Answer:

Matter is made up of particles whose properties determine the observable characteristics of matter and its reactivity.

Explanation:

The gravitational potential energy of a basketball  : PE = 18.375 J

Given

height = h = 3 m

mass = 0.625 kg

Required

The potential energy

Solution

The energy produced from its position is called potential energy (PE)  

which can be formulated as:  

PE = m. g. h (g = 9.8 m/s²)

Input the value :

PE = 0.625 x 9.8 x 3

PE = 18.375 J

Answer:

I hope I can help you

I hope I can help you

Answer:

luster means either sheen/glow or reflected light

Explanation:

luster is the appearance of mineral's surface in terms of light-reflective qualities

Answer:

During the fractional distillation of crude oil: heated crude oil enters a tall fractionating column , which is hot at the bottom and gets cooler towards the top. vapours from the oil rise through the column. vapours condense when they become cool enough.

Hope it helps you :)

The fractionating column's crystal clear glass beads provide such a vast surface area for heated vapors to cool and condensed continuously.

The fractionating column is inserted into the mouth of the distillation flask, which contains the saturated solution to be separated.

Heated crude oil is pumped into a tall fractionating column that is heated at the bottom and cools as it rises.

The oil fumes ascend through the column. When vapors cool down sufficiently, they condense. Various heights are used to lead liquids out of the columns.

Learn more:

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Answer:

the metal is gold I'd say

The mass of one metal atom is [tex]1.770\times 10^{-22}[/tex]grams.

The metal atom is palladium.

Explanation:

Given:

A face-centered unit cell.

The density of the unit cell is [tex]12020 kg/m^3[/tex].

The edge length of the unit cell 389.08 pm

To find:

The mass of one atom of the metal

Solution:

The density of the unit cell = d = [tex]12020 kg/m^3[/tex]

The edge length of the unit cell = a = 389.08 pm

[tex]1 pm = 10^{-12} m\\a=389.08 pm=389.08\times 10^{-12} m=3.8908\times 10^{-10}m[/tex]

Total number of atoms in F.C.C unit cell = z = 4

The atomic mass of the metal atom = M

The density of the unit cell is given by:

[tex]d=\frac{z\times M}{N_A\times a^3}\\12020 kg/m^3=\frac{4\times M}{6.022\times 10^{23}mol^{-1}\times (3.8908\times 10^{-10}m)^3}\\M=0.106586 kg/mol\\1 kg=1000 g\\M=0.106586 kg/mol=0.106586 \times 1000 g/mol\\M=106.586 g/mol[/tex]

The mass of one mole of metal atom = 106.586 g

The mass of 1 atom of metal :

[tex]=\frac{106.586 g}{6.022\times 10^{23}}\\=1.770\times 10^{-22} g[/tex]

The mass of one metal atom is [tex]1.770\times 10^{-22}[/tex] grams.

The atomic mass of the metal atom is 106.586 g/mol which is close to the atomic mass of the palladium. Hence, the metal atom is palladium.

Learn more about the density of unit cell here:

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Answer:

down

Explanation:

Answer

(a) F

Pole Star is a star in the galaxy and hence not a part of the solar system.

(b) T

Mercury is the smallest planet in the solar system and Jupiter is the largest planet in the solar system.

(c) T

Uranus is the farthest planet to the sun in the solar system and Mercury is the closest planet to the earth in the solar system.

(d) T

INSAT or Indian National Satellite System is a series of artificial Indian satellites used for telecommunications, meteorology and search and rescue operations.

(e) F

There are eight planets in the solar system. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Note the pluto is considered as a dwarf planet.

(f) F

Orion can be seen with naked eyes. It is one of the most magnificent constellations in the sky. It has seven or eight bright stars. Orion is also called the Hunter

In this exercise, we have to use our knowledge of astronomy to identify the correct alternatives, so we find that:

1)C

2)B

3)A

4)B

5)D

6)C

Then, based on astronomy knowledge, we can identify that the true alternatives correspond to:

1)A meteor happen a streak of light above bring into being by a meteor superlative through Earth's general feeling or mood.

2)Meteoroids exist lumps of rock or iron that revolution the brightest star, just as celestial body orbiting a star, asteroids, and comets act.

3)A coma happen the fuzzy-anticipate glow that maybe visualize situated on sides the head of a comet.

4)Halley's Comet, that happen 8 kilometres (5 miles) expansive and 16 km long, travels around the Sun each 75 to 76 age in an lengthened circuit.

5)Shooting stars exist existent what astronomers call meteors. Most meteors upset fashionable the gases around the earth before they reach the ground.

6)The celestial body orbiting a star belt happen a torus-form domain in the Solar System, situated about middle from two points the orbits of the celestial body orbiting a star Jupiter and Mars.

See more about  astronomy at brainly.com/question/5165144

Answer:

binary and 11

Explanation:

CaCl2 or Calcium Chloride is an ionic bond and not a covalent bond. Since there should be sharing of electrons between two atoms to be a covalent bonding. In case of calcium chloride, the calcium gives up an electron to each chlorine atom, becoming Ca2+ ions and chlorine become Cl– ions.

:)

Answer:

Your ability to move and lift objects refers to muscular strength. It's measured by how much force you can exert for a short period of time and how much weight you can lift.

Explanation:

Answer:

1. c 2. b that's what i think i learned this in middle school i dont completely remember

Answer:

antimony

Explanation:

it has 51 protons, 4 more than silver and two less than xenon

Answer:

1.023 J / g °C

Explanation:

m = 37.9 grams

ΔT = 25.0*C

H = 969 J

c = ?

The equation relating these equation is;

H = mcΔT

making c subject of formulae;

c = H / mΔT

c = 969 J / (37.9 g * 25.0*C)

Upon solving;

c = 1.023 J / g °C

Answer:

See explanation

Explanation:

The greater the relative atomic  mass of an atom the more polarizable the atom is.

Also, the magnitude of dispersion forces depends on the molecular mass of the compound.

We must remember that both I2 and F2 are nonpolar molecules that are purely held together by dispersion forces.

Hence, I2, having the greater molecular mass and surface area experiences a greater magnitude of dispersion forces and consequently has a higher boiling point than F2.

Answer:

True

Explanation:

Both work because an element would be pure and compounds can be split into elements. This will work unless the substance isnt chemcially pure, but in this case it is so the answer would be true.

Answer:

A reflected ray always comes off the surface of a material at an angle equal to the angle at which the incoming ray hit the surface. In physics, you'll hear this called the law of reflection. You've probably heard this law stated as "the angle of incidence equals the angle of reflection

Explanation:

Answer:

-27 C converted to Kelvin is 246.15 Kelvin.

Explanation:

Hope this helps

Answer:

246.15K

Explanation:

Formula: (-27°)C + 273.15 = 246.15K

Answer:

Umm who's Kyle?

Explanation:

Answer:

his skills aren’t as valuable to the team as he thought

Explanation:

Answer:

The globs rises due to convection.

Explanation:

Convection is when warmer parts move to the top and the cooler parts move to the bottom.  Since the globs are going to be warmer, they rise to the top.

Hope this helps :D

Answer:

20

Explanation:

1.Oort Cloud

2.Uranus Earth and Mars

3.Kuiper Belt

4.Asteroid Belt

Explanation:

Ca3(PO4)2 1 mole has 310.2 g

Ca3(PO4)2 4.3 × 10^-4 moles has 4.3 × 10^-4 × 310.2

= 1,333.86 × 10^-4

= 1.334 × 10^-1

OR 0.1334 g

Answer:

Sand comes from many locations, sources, and environments. Sand forms when rocks break down from weathering and eroding over thousands and even millions of years. Rocks take time to decompose, especially quartz (silica) and feldspar .

Explanation:

Ion knoe Wdym by “be able to describ’ so ima put it in my own words idr lol:)

if you talm bout some kentic energy or sum ok but other Dan dat ion knoe tbh

I can explain how transferring kinetic energy in and out of a substance can cause a change