what is a chemical change? and what is a physical change?

Answer:

the molecules in the reactants interact to form new substances.

Explanation:

Number of moles = 78.41

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

4.72 x 10²⁵ atoms of a substance, then moles :

[tex]\tt n=\dfrac{N}{No}\\\\n=\dfrac{4.72\times 10^{25}}{6.02\times 10^{23}}\\\\n=78.41[/tex]

NaOH is the limiting reactant

Given

12 g of sulfur reacts with 18 g of oxygen and 24 g of sodium hydroxide

Required

The limiting reactant

Solution

Reaction

2 S(s) + 3 O₂(g) + 4 NaOH(aq) ⇒ 2 Na₂SO₄(aq) + 2 H₂O(l)

[tex]\tt \dfrac{12}{32.065}=0.374[/tex]

[tex]\tt \dfrac{18}{32}=0.5625[/tex]

[tex]\tt \dfrac{24}{40}=0.6[/tex]

A method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients, and the smallest ratio becomes a limiting reactant

S : O₂ : NaOH =

[tex]\tt \dfrac{0.374}{2}\div \dfrac{0.5625}{3}\div \dfrac{0.6}{4}=0.187\div 0.1875\div 0.15\Rightarrow NaOH~smallest~ratio[/tex]

Answer:

C

Explanation:

75 mile shallow flat area just off coastlines

N2+3H2-->2NH3

first we find the number of nitrogen moles

the molar mass for N2 is 14+14=28g/mole

to find the number of moles we divide the mass by the molar mass

n=400/28=14.28 moles

for 1 mole of N2 we use 3 moles of H2, therefore for 14.28 moles of N2 we use 14.28*3=42.84 moles ofH2

to find the mass of H2 we multiply the number of moles by the molar mass

the molar mass of H2 is 2g/mole

2*42.84=85.68g of H2

Answer:

33.085476 meV ≈ 33 meV

Explanation:

Hope this helped!

Answer:

2 % de cafe, 20% de azucar, 100% de agua.

Explanation:

Un clásico problema de soluciones:

- Nuestros solutos son 4 g de cafe y 20 g de azúcar.

- en 200 mL de agua

Podemos asumir que los 200mL es el volumen de solución.

%m/v es un tipo de concentración que señala los gramos de soluto en 100 mL de solución.

% m/v de cafe →  (4/200) . 100 = 2 %

% m/v de azucar →  (20/200) . 100 = 20 %

Si tomamos al agua como sustancia que forma parte de la solución sería

(200/200) . 100 = 100 %

Lo que podríamos leer 100 g de agua en 100 mL de agua, dado que la densidad del agua es 1 g/mL

Answer:

0.59 g

Explanation:

The reaction at the first cathode;

Ag^+(aq) + e -----> Ag

if Q = It = 1.5 * 10 * 60 = 900C

According to Faraday's second law of electolysis; if we pass the same quantity of electricity through different electrolytes, the mass of substances deposited on each cathode is proportional to the equivalent weights.

Equivalent weight E = Atomic mass/valency

For Ag = 108/1 = 108

For Ni = 59/2 = 29.5

Hence

Let m1 = mass of Ag deposited =2.16

Let m2 = mass of Ni deposited

Let E1 = equivalent weight of Ag

Let E2 = equivalent weight of Ni

m1/m2 = E1/E2

2.16/m2 = 108/29.5

m2 = 2.16 * 29.5/108

m2 = 0.59 g

Answer:

it would break when it hits the ground

Explanation:

Answer:

Explanation: Elements in group 14 have 4 valence electrons. Meaning that to achieve a stable octet they need to either gain or lose 4 electrons in total. That would take significantly more energy than other elements, e.g., group 1 (alkaline metals) or group 17 (halogens.)

Explanation:

In the periodic table, the elements in column 4 have four valence electrons and are less reactive compared to s- block elements but more reactive than the p-block elements.

Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.

It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.

Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.

Learn more about periodic table,here:

https://brainly.com/question/11155928

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Answer:

A. all other bulbs will no longer work

Answer:

Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. ... Because continental crust is less dense than oceanic crust it floats higher on the mantle, just like a piece of Styrofoam floats higher on the water than a piece of wood does

Answer:

C

Explanation:

To hello fight disease

Answer:

It is difficult to remove electrons from cations because one or more electrons are already lost and hold of nucleus on remaining electrons increase

Explanation:

Answer:

1s^2   2s^2   2p^6    3s^2    3p^6    4s^2    3d^10   4p^6    5s^2    4d^2

Explanation:

Answer:

The carbon dioxide molecule is linear and centrosymmetric at equilibrium. The carbon–oxygen bond length is 116.3 pm, noticeably shorter than the bond length of a C–O single bond and even shorter than most other C–O multiply-bonded functional groups. Since it is centrosymmetric, the molecule has no electrical dipole.

Explanation:

Answer:

The carbon dioxide molecule is linear and centrosymmetric at equilibrium. The carbon–oxygen bond length is 116.3 pm, noticeably shorter than the bond length of a C–O single bond and even shorter than most other C–O multiply-bonded functional groups. Since it is centrosymmetric, the molecule has no electrical dipole.

Carbon dioxide | CO2 | CID 280 - structure, chemical names, physical and chemical ... It is a one-carbon compound, a gas molecular entity and a carbon oxide. ... Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. ... These actions are exploited clinically in the use of hyperventilation to diminish ...

Molecular Formula: CO2

PubChem CID: 280

Molecular Weight: 44.009 g/mol

Chemical Safety: Laboratory Chemical Safety

Answer:

Ketchup is not a change, it is a sauce.

Explanation:

Answer:

There is no change in the tomatos structure its "state of matter" you could say is changed, but the actual chemical compoud is the same.

Answer:

754

Explanation:

Answer:

Explanation:

Given data:

Mass of alcohol = 400 g

Specific heat capacity of alcohol = 2.43 J/g°C

Initial temperature of alcohol = 16°C

Mass of water = 400 g

Specific heat capacity of water = 4.19 J/g°C

Initial temperature of water = 85°C

Final temperature of mixture = ?

Solution:

Equation:

m₁c₁ (T₂-T₁ ) = m₂c₂(T₂-T₁)

by putting values,

400 × 4.19  × (T₂ -  85°C) = 400 × 2.43  × (T₂ - 16°C)

1676  × (T₂ -  85°C) = 972 × (T₂ - 16°C)

Answer:

Please provide answer options. :)

Answer:

d is the correct answer

Explanation:

Answer:

Explanation:

2

Answer:

latent heat of condensation will have the same absolute value as the latent heat of vaporization. The latent heat of condensation will be negative. The latent heat of condensation is a characteristic property that can be used to identify a substance.

Explanation:

Answer:

energy absorbed or released by a substance during a change in its physical state (phase) that occurs without changing its temperature.

Explanation:

Answer:

Moon

Explanation:

Answer:

An acid is the specie which can donate a proton.

Explanation:

Bronsted lower acid:

An acid is the specie which can donate a proton.

Bronsted lower base:

A base is the specie that can accept the proton.

For example:

HCl + NH₃     →       NH₄⁺ + Cl⁻

Here in this reaction HCl is act an acid because it donate the proton while NH₃ is Bronsted lower base because it accept the proton.

Bronsted lowery acid = proton donor

Bronsted lowery base = proton accepter

Answer:

B) we will convert the 10 g of NaCl into moles.

Explanation:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

we will convert the 10 g of NaCl into moles.

Number of moles of NaCl:

Number of moles = mass/molar mass

Number of moles = 10 g/ 58.44 gmol

Number of moles = 0.17 mol

1 Kg = 1 L

Molarity = 0.17 mol / 2 L

Molarity = 0.085 mol/L

Molarity = 0.085 M

Answer:

B. Convert the 10g of NaCl to moles of NaCl

Answer:

young soil has less organic materiel that old

Explanation:

Answer:

4k^2-4k+1

Explanation:

Plx give brainlyest