Can someone help me with these three questions? please

Answer:

Chemical changes due to heat and pressure

Explanation:

Just took the test, hope this helps! :)

Answer:

Chemical changes due to heat and pressure

Explanation:

I took this test and got a 100%! :D

Answer:

???????????????????????

Answer:

river or lake

Explanation:

Answer:

you r correct it is layer a and b

Explanation:

Answer:

Explanation:

B I got it right

Answer:

B. The ball will gain kinetic energy, and the racket will lose kinetic

energy

Explanation:

Answer:

the answer for 5 is liquid

Answer:

d

Explanation:

Answer:

0.43mole

Explanation:

Given parameters:

Mass of C₂H₆   = 13g

Unknown:

Number of moles  = ?

Solution:

To solve this problem we need to first find the molar mass of the given compound.

 Molar mass of C₂H₆ = 2(12) + 6(1)  = 30g/mol

So;

 Number of moles  = [tex]\frac{mass}{molar mass}[/tex]  

Number of moles  = [tex]\frac{13}{30}[/tex]    = 0.43mole

Answer:

52.257%

Explanation:

Answer:

combination, decomposition, single-replacement, double-replacement, and combustion.

Explanation:

Answer:DNA

Explanation:Dna

The volume of H₂ : = 15.2208 L

Given

Reaction

2 As (s) + 6 NaOH (aq) → 2 Na₃AsO₃ (s) + 3 H₂ (g)

34.0g of As

Required

The volume of H₂ at STP

Solution

mol As (Ar = 75 g/mol) :

= mass : Ar

= 34 g : 75 g/mol

= 0.453 mol

From the equation, mol ratio As : H₂ = 2 : 3, so mol H₂ :

=3/2 x mol As

=3/2 x 0.453

= 0.6795

At STP, 1 mol = 22.4 L, so :

= 0.6795 x 22.4 L

= 15.2208 L

Answer:

2.8 X 10-5s in standard notation is 28-5s

Explanation:

Multiply 2.8 by 10

Answer:

Problem: The Ba3(PO4)2 (molar mass = 601.93 g/mol) precipitate that formed from a salt mixture has a mass of 0.667 g.

The molar mass of barium phosphate is 601.93 g/mol.

Molar mass is defined as the mass of a compound divided by the number of moles which is the amount of substance .It is a bulk quantity and not a molecular property of a substance . They are mostly calculated by adding the atomic masses of constituent elements in a compound.

It is an average of many particles or molecules.Molar mass is an intensive property as it does  not depend on size of the sample.It has units of kg/mol. Molar masses of elements is given by relative atomic mass of element whereas that of compounds is given by the sum of relative atomic mass multiplied by the molar mass constant.

They are never measured directly , they are measured from the standard atomic masses.

Learn more about molar mass,here:

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Answer:

5.36 × 10²³ molecules

Explanation:

Given data:

Number of moles of silver = 0.89 mol

Number of molecules = ?

Solution:

Avogadro number:

The number 6.022 × 10²³ is called Avogadro number.  

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

Number of molecules of silver:

1 mole contain 6.022 × 10²³ molecules

0.89 mol  ×  6.022 × 10²³ molecules /1 mol

5.36 × 10²³ molecules

Answer:

Biology

Explanation:

I'm currently taking highschool biology right now and it's a lot of fun. If you like animals and cells, a lot of fun.

Answer:

Chemical reaction

Explanation:

After new substances are formed they can't be reversed to their original state.

Answer:

aluminum nitride

Explanation:

i think

Explanation:

When a metal replaces another metal in solution, we say such a reaction has undergone a single displacement reaction.

In such a reaction, metal higher up in the activity series replaces another one due to their position.

To known the metal or metals that will replace the given copper, we need to reference the activity series of metals.

Every metal higher than copper in the series will displace copper from the solution.

So, there metals are: potassium, sodium, lithium, barium, strontium etc.

Answer:

so is this a project or a quiz

Answer:

Structural formula

Explanation:

Various type of formulae describe an organic compound. The empirical formula only shows the ratio of atoms of each element present. The molecular formula shows the exact number of atoms of each element present.

Lastly, the structural formula shows us the arrangement of these atoms in space. It shows us the number of atoms, nature and bond types in organic compounds​.

The structural formula enables us to picture what the real molecule must look like.

Answer:

b

Explanation:

Answer:

aluminum

no aluminum is left over

Explanation:

the next answers for step 7 are 0.019, 0.0093, aluminum

Answer:

Aluminum because no aluminum is left over

Explanation:

Answer:

7.5 moles of hydrogen is required

Explanation:

Given data:

Number of moles of H₂ needed = ?

Number of moles of NH₃ = 5 mol

Solution:

Chemical equation:

N₂ + 3H₂     →     2NH₃

Now we will compare the moles of ammonia and hydrogen.

         NH₃       :         H₂  

          2           :          3

          5           :         3/2×5 = 7.5 mol

Thus, 7.5 moles of hydrogen is required.

The final volume : 807.69 cm³

Given

Initial volume : 840 cm³

Initial pressure : 750 mmHg

Final pressure : 780 mmHg

Required

The final volume

Solution

Boyle's Law  

At a fixed temperature, the gas volume is inversely proportional to the pressure applied  

[tex]\tt p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]

Input the value :

V₂=(P₁V₁)/P₂

V₂=(750 x 840)/780

V₂=807.69 cm³

Answer:

H2SO4

Explanation:

Firstly,

2.056% hydrogen = 2.056g of H

32.69% Sulphur = 32.69g of S

65.26% oxygen = 65.26g of O

Next, we convert each mass into moles by dividing by their respective molar mass:

H = 1, S = 32, O = 16

H = 2.056/1 = 2.056mol

S = 32.69/32 = 1.021mol

O = 65.26/16 = 4.078mol

Next, we divide each mole value by the smallest mole value (1.021)

H = 2.056/1.021 = 2.01

S = 1.021/1.021 = 1

O = 4.078/1.021 = 3.99

Approximately the ratio of H to S to O is 2:1:4, hence, the empirical formula for H, S and O is H2SO4.

The empirical formula of a chemical compound is the simplest whole-number ratio of atoms present in a compound

The correct answer of the following is [tex]H_2SO_4[/tex]

The data is given as follows:-

We have to find the moles in the reaction.

The mas of the element is as follows:-

After solving the equation we get

[tex]H = \frac{2.056}{1} = 2.056mol\\\\S = \frac{32.69}{32} = 1.021mol\\\\O = \frac{65.26}{16} = 4.078mol[/tex]

Next, we divide each mole value by the smallest mole value (1.021)

[tex]H = \frac{2.056}{1.021} = 2.01\\\\S = \frac{1.021}{1.021} = 1\\\\O = \frac{4.078}{1.021} = 3.99[/tex]

The ratio of H to S to O is 2:1:4,

Hence, the empirical formula for H, S, and O is [tex]H_2SO_4.[/tex]

For more information, refer to the link:-

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