One way of purifying gaseous H2 is to pass it under high pressure through the holes of a metal's crystal structure. Palladium, which adopts a cubic closest packed structure, absorbs more H2 than any other element and is one of the metals currently used for this purpose. Although the metal-hydrogen interaction is unclear, it is estimated that the density of absorbed H2 approaches that of liquid hydrogen (70.8 g/L). What volume (in L) of gaseous H2, measured at STP, can be packed into the spaces of 1 dm3 of palladium metal

A magnesium ribbon is cleaned to remove the protective layer of basic magnesium carbonate from its surface, so that it may readily combine with the oxygen in air (on heating).

Answer:

Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.

Answer:

1. Na2CO3 + 2HCl --> 2NaCl + CO2 + H2O

2. 2NaOH + H2SO4 --> Na2SO4 + H2O

3. CaCO3 + 2HCl --> CaCl2 + CO2 + H2O

4. 4Na + O2 --> 2Na2O

Answer:

3.01×10²⁶ molecules

Explanation:

From the question given above, the following data were obtained:

Mass of H₂ = 1 Kg

Number of molecules =?

From Avogadro's hypothesis,

1 mole of H₂ = 6.02×10²³ molecules

But 1 mole of H₂ = 2 × 1 = 2 g

Now, we shall determine the number of molecules present in 1 Kg (i.e 1000 g) of H₂ as follow:

From Avogadro's hypothesis,

2 g of H₂ = 6.02×10²³ molecules

Therefore,

1000 g of H₂ = 1000 × 6.02×10²³ / 2

1000 g of H₂ = 3.01×10²⁶ molecules

Thus, the number of molecules present in 1 Kg (i.e 1000 g) of H₂ is 3.01×10²⁶ molecules

Answer; a) Covalent compound are formed when atoms of different molecules share electrons in order to be stable either by losing or gaining electrons

eg.. HCL hydrogen chloride , a chlorine atom has 7 electrons on its outer shell and hydrogen has 1 so when this two pair they become covalently bonded. chlorine shares one electron with the hydrogen atom ,thus to say both now have a stable arrangement of electron in their outer shell.

methane CH4 the carbon atom has 4 electrons and hydrogen has 1 so carbon would need 4 more and hydrogen would need 1 more so carbon pairs with 4 hydrogen atoms making it 8 and hydrogen 2 so they now have a stable arrangement ,thus the carbon atom shares with 4 hydrogen atoms.

b) some physical properties are

i)they have low melting and boiling points

ii)their insolubility in water

iii) they are non conductors of electricity

c) an experiment using their melting and boiling point

EXPERIMENT; lets use the covalent molecule carbon monoxide CO

when you apply heat and it tend to melt at a -199 degree celsius then it is a covalent molecule

and when it starts to boil at -191 degree celsuis then its sure a carbon monoxide covalent molecule

explanation; the reason for its low melting point and boiling point is because the attraction between the molecule is very low so it doesn't need much energy to break up the lattice between them.

HOPE THIS HELP if you need more explanation feel free to comment in the comment section

Answer:

a group of electrochemical cells that can be recharged

Answer:

C

they store genetic information

B. They speed up chemical reactions

Answer:

1: because phosphate contain oxide ions so that is base character

MOUNTAINS

Mountains are large, tall, and elevated land areas on the earth's surface. They have steep, sloping sides and sharp or rounded ridges, and a high point, called a peak.

PLAINS

Plains are one of the major landforms on earth. They are areas of flat lands.

PLATEAUS

A plateau is a flat, elevated landform that rises above the surrounding area.

DESERTS

Regions of dry, arid lands.

DELTAS

A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water.

Answer:

Inference

Explanation:

A conclusion reached on the basis of evidence and reasoning is called an inference.

Answer:

B is correct answer because The enthalpy is negative so this means the reaction produces heat and the reaction is exothermic

Answer:

Less

More

Explanation:

When a constraint is imposed on a reaction system in equilibrium, the equilibrium position will shift in such a way as to annul the constraint.

When the volume of a reaction system in equilibrium is decreased, the equilibrium position will shift in the direction having less total number of moles.

Similarly, when the volume is increased, the equilibrium position shifts to the direction having a greater total number of moles.

Answer: b and d

Explanation:

1×10^-3=1×1/10³=1×1/1000=1/1000 so b is correct

1×10^-3=1/1000=0.001

so d is correct

Answer:

1. Isotope with mass number 39.

2. 39.02g/mol

Explanation:

1. The most common isotope is the isotope in the higher proportion, that is:

Isotope with mass number 39.

2. The average atomic mass is the sum of the masses times their abundance. For the element X:

Average atomic mass:

38*0.0967 + 39*0.7868 + 40*0.1134 + 41*0.0031

= 39.02g/mol

Answer: lysocline

Explanation:

Lysocline is the depth in the ocean at which calcareous skeletal material first begins to dissolve. It is the depth of the ocean whereby the dissolution rate of calcite has a dramatic rise.

Lysocline is also referred to as the transition zone upper bound where the CaCO3 content drops.

Answer:

Scientific Method

Explanation:

Science is empirical in nature. The entire purpose of science is to discover new knowledge.

The empirical research method in science all begins with gathering observations from phenomena. After that, the researcher formulates appropriate hypothesis which are rigorously tested.

The conclusions drawn from testing the original hypothesis validate or modify the original hypothesis.

Answer:

mg2+ because it is a very good idea

Answer:

A standard system of measurement is very important because it helps us from making mistakes at the moment of doing calculations and correctly working...

Answer:

A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results. Metric System – is a measurement system based on the number 10.

Answer:

0.535 atm

Explanation:

Since the volume of the tank is constant, we use Gay- Lussac's law to find the pressure at 180°C.

So, P₁/T₁ = P₂/T₂ where P₁ = pressure at S.T.P = 1 atm, T₁ = temperature at S.T.P = 273.15 K, P₂ = pressure of gas at 180 °C and T₂ = 180 °C = 273.15 + 180 K = 453.15 K

So, P₁/T₁ = P₂/T₂

P₂ = P₁T₂/T₁

Substituting the values of the variables into the equation, we have

P₂ = P₁T₂/T₁

P₂ = 1 atm × 453.15 K/273.15 K

P₂ = 1 atm × 1.66

P₂ = 1.66 atm

We now need to find the total number of moles of each gas present

number of moles of nitrogen = mass of nitrogen, m/molar mass of nitrogen molecule M

n = m/M

m = 2.5 g and M = 2 × atomic mass of nitrogen (since it is diatomic) = 2 × 14 g/mol = 28 g/mol

So, n = 2.5 g/28 g/mol

n = 0.089 mol

number of moles of chlorine, n' = mass of chlorine, m'/molar mass of chlorine molecule M'

n' = m'/M'

m' = 13.3 g and M = 2 × atomic mass of chlorine (since it is diatomic) = 2 × 35.5 g/mol = 71 g/mol

So, n' = 13.3 g/71 g/mol

n' = 0.187 mol

So, the total number of moles of gas present is n" = n + n' = 0.089 mol + 0.187 mol = 0.276 mol

So, the partial pressure due to nitrogen gas, P = mole fraction of nitrogen × pressure of gas at 180 °C

P = n/n" × P₂

P = 0.089 mol/0.276 mol × 1.66 atm

P = 0.322 × 1.66 atm

P = 0.535 atm

Answer:

This is the chemical formula for calcium phosphate:

[tex]Ca_3(PO_4)_2[/tex].

Calculate the mass percent of oxygen in calcium phosphate. Round your answer to the nearest percentage

Explanation:

The molar mass of calcium phosphate is: 310.18g/mol.

In one mole of calcium phosphate there are 8 moles of oxygen atoms.

The atomic mass of oxygen in calcium phosphate is: 128.0 g

Hence, the mass % of oxygen in the given compound is:

[tex]mass% of Oxygen =\frac{mass of oxygen}{mass of calcium phosphate}*100\\&=\frac{128.0g}{310.18g} *100\\&=41.3[/tex]

Hence,mass%of oxygen is 41.3.

Answer:

Wavelength = 0.049 m

Explanation:

Given that,

The frequency of a wave,[tex]f=6.1\times 10^9\ Hz[/tex]

We need to find the wavelength of the wave. We know that,

[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{2.998 \times 10^8}{6.1\times 10^9}\\\\\lambda=0.049\ m[/tex]

So, the wavelength of the wave is 0.049 m.

Answer:

I'm pretty sure this is propanediol

Explanation:

I'm not sure how to explain it, but I believe this is the structure for propanediol. Please let me know if I misunderstood and don't hesitate to reach out with questions!

1,3-propan-diol is the chemical name the given structure: [tex]HOCH_2CH_2CH_2OH[/tex].

Chemical names are orderly systems for classifying and identifying various chemical compounds. They act as a benchmark for international scientific and research communication. For the development of many scientific domains, a standardised nomenclature system for chemicals must be created and adopted. Chemical names, which are made up of a combination of words and symbols, include detailed information on the make-up and structure of a certain substance. They frequently contain constituents, functional groups, and distinct modifiers that aid in describing the compound's varied attributes. 1,3-propan-diol is the chemical name the given structure: [tex]HOCH_2CH_2CH_2OH[/tex].

To know more about chemical name, here:

https://brainly.com/question/30633673

#SPJ6

Using the idea of the  molar volume of butane gas, we have 2.23 moles of water vapor.

The term reaction equation shows the conversion of reactants to products. First of all, we must get down the reaction equation as follows;

C4H10(g) + 13/2O2(g) ----> 4CO2 (g) + 5H2O(g)

From the balanced reaction equation;

1 mole of  butane gas yields 5 moles of water vapor. Since 1 mole of butane gas occupies 22.4 L. Hence;

22.4 L of butane yields 5 moles of water vapor

10 L of butane gas yields 10 L * 5 moles/22.4 L = 2.23 moles

Learn more about butane gas:https://brainly.com/question/6665698

Answer:

i hope it will help you

Explanation:

there will be 7 electrons and 9 protons will have 2+ charge.

Answer:

false, The nucleus of atoms still move around like crazy, it's just the electrons move more.

Answer:

Liquid

Explanation:

Quite an easy question!

Answer:

Liquid

Explanation:

I was passing by lol

Answer:

4.95L

Explanation:

Using Charle's law equation;

V1/T1 = V2/T2

Where;

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the question, the following information was given:

V1 = 4.50L

V2 = ?

T1 = 27°C = 27 + 273 = 300K

T2 = 57°C = 57 + 273 = 330K

Using V1/T1 = V2/T2

4.50/300 = V2/330

Cross multiply

300 × V2 = 4.5 × 330

300V2 = 1485

V2 = 1485 ÷ 300

V2 = 4.95L

Answer:

=0.15M

Explanation:

To get the moles of the unknown LiOH, calculate the number of moles of HCl in 12.3mL.

Using the stoichiometric coefficient, mole ratio 1:1.

This means that the number of moles is the same. This number of moles is contained in 18mL. Then Calculate the molarity (concentration) which is in 1000mL

See the explanation from the image I have shared with you for calculations.

[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]

Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.

Hope it helps uh ✌️✌️✌️