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4 years ago

Plz help! What needs to be added or taken away to cause a change in state?

Chemistry

1 answer:

stepladder [879]4 years ago

4 0

Answer:

One change of state happens when you add energy to the substance. This change of state is called melting. By adding energy to the molecules in a solid the molecules begin to move quicker and can break away from the other molecules.

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They will not have to pay any cost because the accident was not Dave’s fault, Eli will be covered by Dave’s family car insurance policy, they will be protected by the other driver’s insurance. (B,C,D)

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3 years ago

Describe the process of organic vegetable production.

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Explanation:

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3 years ago

How many grams are in .705 moles of Cr?

Kruka [31]

Answer: 51.9961 grams.

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3 years ago

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A car speeds up from 0 km/hr to 100 km/hr in 6 seconds.

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3 years ago

Please answer these!!!

olasank [31]

Answer:

1.b. 2.5 mol

2.c.82.8%

3.d. synthesis

4.c . 2:2

5.d. 5 moles

6.c.5.02

7.d.3:1

8.d.2.68 moles

Explanation:

$2RbNO_{3}\rightarrow 2RbNO_{2}+1O_{2}$

Here , 2 mole of RbNO3 will produce, 1 mole of O2

1 mole of RbNO3 will produce =

$\frac{1}{2}$ mole of O2

5 mole of RbNO3 will produce =

$\frac{1}{2}\times 5$

2 .

Molar mass of HCl = 1 + 35.45 = 36.45 gram

Molar mass of CO2 = 12 +32 = 44 gram

1 mole of the substance = molar mass

So , 1 mole of HCl = 36.45 gram

2 mole of HCl = 2 x 36.45 =72.9 gram

1 mole of CO2 = 44 gram

The given equation is :

$CaCO_{3}+2HCl\rightarrow CO_{2}+H_{2}O$

Here CaCO3 is the excess reagent and HCl is the limiting reagent

2 mole of HCl will produce = 1 mole of CO2

72.9 gram of HCl= 44 gram of CO2

so, 1 gram of HCl =

$\frac{44}{72.9}$ gram of CO2

Here we need to calculate the mass of CO2 in 200 gram of HCl.

So, 200 gram of HCl =

$\frac{44}{72.9}\times 200$ gram CO2

=120.71 gram CO2

this is the theoritical yield of CO2 = 120.71 gram

Experimental yield = 100 gram (given)

The percent yield is calculated by:

$=\frac{Experimental}{Theoritical}\times 100$

$=\frac{100}{120.71}100$

= 82.84%

3.Synthesis Reaction : Those reactions in which two or more substances combine to give a single product.

Here NH3 and HCl are combined and giving only one product = NH4Cl

$2H_{2}+1O_{2}\rightarrow 2H_{2}O$

Hydrogen = H2

Water = H2O

Here Ratio of H2 to H2O is 2:2

5.The balanced equation is :

$1Ca(OH)_{2}+2HCl\rightarrow 1CaCl_{2}+2H_{2}O$

The number of atoms on left side should be equal to the right side:

Ca = 1

H = 4

O = 2

Cl = 2

Here, 2 moles of water(H2O) = 2 moles of HCl

So, 5 moles of water will give = 5 moles of HCl

$2Ag(NO)_{3}+BaCl_{2}\rightarrow 2AgCl_{2}+BaNO_{3}$

Molar mass of AgNO3 = 169.87 g/mol

1 mol of AgNO3 = 169.87 gram

Molar mass of AgCl = 143.32 g/mol

1 mole of AgCl = 143.32 grams

According to the given equation ,

2 mole of AgNO3 will give = 2 mole of AgCl

1 mole of AgNO3 = 1 mole of AgCl

169.87 gram of AgNO3 = 143.32 gram of AgCL

1 gram of AgNO3 =

$\frac{143.32}{169.87}$

5.95 gram of AgNO3 =

$\frac{143.32}{169.87}\times 5.95$

= 5.02 grams

7. The mole ratio of Hydrogen (H2) to Nitrogen (N2):

$N_{2}+3H_{2}\rightarrow 2NH_{3}$

H2 = 3 mole

N2 = 1 mole

[H2]:[N2] = 3:1

8. The moles in a substance can be calculated by using :

$moles=\frac{Mass}{Molar\ mass}$

Mass of N2 = 75 grams (Given)

Molar mass = 28 gram

$moles=\frac{75}{28}$

Moles = 2.678 moles

8 0

3 years ago