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alisha [4.7K]
3 years ago
15

A-potassiumB-leadC-ironD-magnesiumE-zinc​

Chemistry
1 answer:
viktelen [127]3 years ago
6 0

The unknown substance : Lead

<h3>Further explanation</h3>

Given

Density of element

mass of unknown substance = 40 g

volume = 3.5 cm³

Required

The density of unknown substance

Solution

Density is the ratio of mass per unit volume  

The unit of density can be expressed in g/cm³ or kg/m³  

Density formula:  

\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}

Input the value to find the density of an unknown substance :

ρ = 40 g : 3.5 cm³

ρ = 11.43 g/cm³

If we look at the table, the substance which has a density of 11.43 is Lead

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2C₂H6 + 702 —&gt;4C02 + 6H₂O
navik [9.2K]

Answer:

975.56×10²³ molecules

Explanation:

Given data:

Number of molecules of C₂H₆ = 4.88×10²⁵

Number of molecules of CO₂ produced  =  ?

Solution:

Chemical equation:

2C₂H₆  + 7O₂     →      4CO₂ + 6H₂O

Number of moles of C₂H₆:

1 mole = 6.022×10²³ molecules

4.88×10²⁵  molecules×1mol/6.022×10²³ molecules

0.81×10² mol

81 mol

Now we will compare the moles of C₂H₆ with CO₂.

                     C₂H₆          :             CO₂

                          2           :               4

                           81         :           4/2×81 = 162 mol

Number of molecules of CO₂:

1 mole = 6.022×10²³ molecules

162 mol ×6.022×10²³ molecules / 1 mol

975.56×10²³ molecules

8 0
3 years ago
A boy with pneumonia has lungs with a volume of 1.7 L that fill with 0.070 mol of air when he inhales. When he exhales, his lung
BlackZzzverrR [31]

Answer:

0.053moles

Explanation:

Hello,

To calculate the number of moles of gas remaining in his after he exhale, we'll have to use Avogadro's law which states that the volume of a given mass of gas is directly proportional to its number of moles provided that temperature and pressure are kept constant. Mathematically,

V = kN, k = V / N

V1 / N1 = V2 / N2= V3 / N3 = Vx / Nx

V1 = 1.7L

N1 = 0.070mol

V2 = 1.3L

N2 = ?

From the above equation,

V1 / N1 = V2 / N2

Make N2 the subject of formula

N2 = (N1 × V2) / V1

N2 = (0.07 × 1.3) / 1.7

N2 = 0.053mol

The number of moles of gas in his lungs when he exhale is 0.053 moles

7 0
3 years ago
I WILL GIVE BRAINLEST ANSWER THOSE THREE QUESTIONS PLZZZZ HELP ME
miskamm [114]
For changing potential energy; When you drop a book, gravitational potential energy is transformed into kinetic energy. Your car transforms the chemical potential energy stored in gasoline into the kinetic energy of the car's motion.

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3 0
3 years ago
What’s the two products of H2Co3
forsale [732]

Answer:

Hydrogen and Cobalt

Explanation:

Break up each individual element

- Hope that helps! Please let me know if you need further explanation.

6 0
3 years ago
How does increasing the temperature affect collisions?
ddd [48]
Combustion Have a great day!
8 0
3 years ago
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