How can the percentage of air be determined

Answer:

Ammonium chloride, iron ,Sulphur and salt mixed together... they can be separated in the following methods.

1. Ammonium chloride is separated by sublimination... NC4CI is sublimable. Heat the mixture in a china dish and collect the funds of NC4CI (sublimable substance)

2. Bring a magnet close to the remaining mixture. Iron is magnetic substance and thus, it will be attracted towards the magnet. Iron is separated.

3. Sulphur is insoluble in water and salt is soluble. Add water to the remaining mixture and then wait for sedimentation. Separate the sulphur by decantation.

4. Heat the filtered salt solution to obtain salt.

The answer is 32 grams!

hope I helped

Answer:

Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.

Example: Water decomposes into a mixture of hydrogen and oxygen when an electric current is passed through the liquid. Hydrogen and oxygen, on the other hand, cannot be decomposed into simpler substances. They are therefore the elementary, or simplest, chemical substances - elements.

Each element is represented by a unique symbol. The notation for each element can be found on the periodic table of elements.

The elements can be divided into three categories that have characteristic properties: metals, nonmetals, and semimetals. Most elements are metals, which are found on the left and toward the bottom of the periodic table. A handful of nonmetals are clustered in the upper right corner of the periodic table. The semimetals can be found along the dividing line between the metals and the nonmetals.

Explanation:

Answer:

Explanation:

1) person 2 had a slightly higher blood glucose level than person 1 after fasting 12 hrs (0.2mmols)

2) person 3 has a much higher blood glucose level than person 1 after taking glucose (5.6mmols)

3) insulin

Explanation:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

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Answer:

Check Down

Explanation:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bond.

Answer:

don't know..............

Answer:

As the ballon rises higher the atmospheric pressure will drop if the ballon is made of an elastic material,it will stretch to allow the gas inside it to expand

Answer:

sry i don't know answer of This question

Answer:

The correct answer is - alpha particle and positron.

Explanation:

In this question, it is given that, 38^88Sr decays to 34^84Kr, which means there is an atomic number decrease by 4, 38 to 34, and atomic mass decreases by 4 as well 88 to 84.

A decrease in the atomic mass is possible only when there is an emission of the alpha particle as an alpha particle is made of 2 protons and 2 neutrons. If an atom emits an alpha particle, there is a change in atomic number as it decreases by two, and its mass number decreases by four.

So after the emission of an alpha particle, the new atom would be

38^88Sr=> 36^84X => 34^84Kr

so there is also two positron emission that leads to decrease in atomic number by one with each emission:

38^88Sr=> 2^4He+ 36^84X => 36^84X + 2(1^0β+) => 34^84Kr

Positron decay is the conversion of a proton into a neutron with the emission of a positron that causes the atomic number is decreased by one, which causes a change in the elemental identity of the daughter isotope.

The products formed during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.

ELECTROLYSIS is the process by which electrolytes allows electric current to pass through it and is decomposed on the process.

CHLORINE is an element which can be produced industrially through the process of electrolysis of brine (concentrated sodium chloride solution). When sodium chloride is dissolved in water, it's ions separate and are capable of conducting electricity.

The products formed during this process includes:

CHLORINE: this is released at the positive electrode during electrolysis. It is used for the following purposes:

SODIUM HYDROXIDE: this remains in the solution during electrolysis. It is used for the following:

HYDROGEN GAS:this is released at the negative electrode during electrolysis. this is used for the following:

Therefore other products during electrolysis of concentrated sodium chloride solution are SODIUM HYDROXIDE and HYDROGEN GAS.

learn more here:

https://brainly.com/question/13123512

Explanation:

"Its bonds are formed by large differences in electronegativity" is the statement among the choices given in the question that is generally true about CaCl2.

Answer:

1 Anomalous Pairs. The rest of the  pairs of elements don't follow the follow Mendeleev's Principles . they are :

2Grouping of chemically dissimilar elements.  

3Position of Isotopes.  

4Electronic arrangement.  

5Separation of chemically similar elements.  

6The position of hydrogen.

Answer:

The correct answer is - Economic concerns may prevent it from solving problems.

Explanation:

Scientific research is influenced by various factors. Science helps in the solving of human problems. However, scientific research can need to be supported by many factors such as Huge amounts of money that need to be invested in performing out particular scientific research to solve problems.

For science, there are requirements of Laboratories and lab supplies such as the equipment and experts need to train the personnel on how to use it.

Thus, economic factors play a huge role in scientific research.

Answer:

Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell

Answer:

1 Ca(NO3)2

Calcium- Ca, Valency 2

Nitrate- NO3, Valency 1

AFTER CRISS CROSS:

Ca1(NO3)2

Ca(NO3)2

2 sodium bicarbonate = NaHCO3

Na = Sodium = (Na)+

HCO3 = bicarbonate = (HCO3) -

Na HCO3

3 magnesium   nitrite

   +2                 _ 1

Mg2(NO3)2

4 Na    Cl

    +1    _1

formula NaCl

5 hydrogen         sulphide  

H                       SO4

+1                       _2

formula H2SO4

6  H    Cl

  +1     _1

HCl

7 AL2     HSO4

  +2        -2

AL2(HSO4)3

8  NH4   Cl

   +1      _1

NH4Cl

9 NH4     SO4

  +1           _2

(NH3)2SO4

10  H   NO3

    +1    _1

HNO3

Answer:

0.7602 g/L

Explanation:

We'll begin by calculating the molar mass of NH₃. This can be obtained as follow:

Molar mass of NH₃ = 14.01 + (3×1.01)

= 14.01 + 3.03

= 17.04 g/mol

Finally, we shall determine the density of ammonia, NH₃. This can be obtained as follow:

Temperature (T) = 273 K

Pressure (P) = 1 atm

Molar mass of NH₃ (M) = 17.04 g/mol

Gas constant (R) = 0.0821 atm.L/Kmol

Density (D) =?

D = PM / RT

D = (1 × 17.04) / (0.0821 × 273)

D = 17.04 / 22.4133

D = 0.7602 g/L

Answer:

It is A

Explanation:

Answer:

how will I show?

Explanation:

pLS teacher me

2HCl + Mg => MgCl2 + H2

Answer:

b. They do not move through the rock cycle at the same rate

Explanation:

The rock cycle is the phenomenon used to describe the interrelation of the three forms in which rocks exists, and a rock is changed between forms due to the Earth's geologic process, such as erosion, weathering and plate tectonics

The rock cycle involves both chemical and physical transformation of rocks and therefore, the atoms and compounds make and cut connections, such that the rate at which each atom move through the rock cycle at different rate

Answer:

in sodium sulphate there is sodium an sulphur

Answer:

hydrogen is abundant in nature

Answer:

a. 1 x 10^-35

Explanation:

The correct compound given is: [tex]\mathsf{Cu_3(AsO_4)}_2[/tex]

To predict the approximate Ksp value of the given compound, we will need to express the oxidation-reduction half-reaction of the compound and its dissociation, then, we will use the Nernst equation to determine the approximate Ksp value.

To start with the reduction half-reaction:

[tex]\mathsf{Cu_3(AsO_4)_{2}(s) + 6e^- \to 2As O_{4}^{3-}_{(aq)}+3Cu(s) }[/tex]

The oxidation half-reaction is:

[tex]\mathsf{3Cu(s) \to 3CU^{2+}_{(aq)} + 6e^-}[/tex]

The overall cell reaction now is:

[tex]\mathsf{Cu_3(AsO_4)_{2}(s) \to 3Cu^+ (aq) + 2As O_{4}^{3-}_{(aq)} }[/tex]

From the reduction half-reduction, the number of moles of electrons (n) transferred is 6 moles.

By applying the Nernst equation:

[tex]\mathsf{E_{cell} = E^0_{cell} -\dfrac{0.0591V}{n}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]

At standard conditions;

The standard cell potential [tex]\mathsf{E^0_{cell} = -0.342 \ V}[/tex]

and [tex]\mathsf{E_{cell} = 0 \ V}[/tex] since it is at equilibrium.

∴

[tex]\mathsf{0 = -0.342 -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 } \\ \\ \\ \mathsf{0.342 = -\dfrac{0.0591V}{6}log [Cu^{2+}]^3[AsO_4^{3-}]^2 }[/tex]

[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = \dfrac{-(0.342)*6}{0.0591 }}[/tex]

[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 = -34.7}[/tex]

[tex]\mathsf{log [Cu^{2+}]^3[AsO_4^{3-}]^2 \simeq -35}[/tex]

[tex]\mathsf{[Cu^{2+}]^3[AsO_4^{3-}]^2 = 10^{-35}}[/tex]

[tex]\mathbf{K_{sp} = [Cu^{2+}]^3[AsO_4^{3-}]^2 = 1\times 10^{-35}}[/tex]

Answer:

The answer is B. A hydrogen atom forms a convalent bond.........

Answer:

B. Transfer energy to reaction center chlorophylls.

Explanation:

Accessory pigments absorbs sunlight, these compounds are found in photosynthetic organisms, which work in conjunction with chlorophyll. Acessory pigments absorbs and transfer light energy to reaction center chlorophylls.

Explanation:

an acid will give away a proton and become a conjugate base.

A base will accept a proton and become a conjugate acid.

Answer:

The molar mass of gas Q is 43.923 g/mol

Explanation:

The given volume of ethane gas that diffuses through a porous plug in 100 seconds = 100 cm³

Therefore;

The rate of diffusion of ethane gas through the porous plug, [tex]v_{ethane}[/tex], is given as follows;

[tex]v_{ethane}[/tex] = (100 cm³/100 s) = 1 cm³/s

The molar mass of ethane, C₂H₆ = 2×12 g/mol + 6×1 g/mol = 30 g/mol

The given volume of gas, Q, that diffuses through a porous plug in 121 seconds = 100 cm³

∴ The rate of diffusion of the gas, Q, [tex]v_Q[/tex] = 100/121 cm³/s

Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of the molecular mass of the gas

Mathematically, we have;

[tex]\dfrac{v_A}{v_B} =\sqrt{\dfrac{m_B}{m_A} }[/tex]

Where;

[tex]v_A[/tex] = The rate of diffusion of gas A

[tex]v_B[/tex] = The rate of diffusion of gas B

[tex]m_A[/tex] = The molar mass of the gas A

[tex]m_B[/tex] = The molar mass of the gas B

Therefore, for ethane and gas Q, measured under the same condition, we have;

[tex]\dfrac{v_{ethane}}{v_Q} =\sqrt{\dfrac{m_Q}{m_{ethane}} }[/tex]

[tex]\dfrac{1 \ cm^3/s}{\dfrac{100}{121} \ cm^3/s} =\sqrt{\dfrac{m_Q}{30 \ g/mol} }[/tex]

[tex]m_Q = \left ({\dfrac{121}{100} } \right) ^2 \times 30 \ g/mol = 43.923 \ g/mol[/tex]

The molar mass of gas Q, [tex]m_Q[/tex] = 43.923 g/mol.

Answer:

1. Fr

2. cl

3.H20

4.2 mole

5. 3

6. c