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3 years ago

When was copper discovered?

Chemistry

1 answer:

Vesna [10]3 years ago

3 0

Answer:

9000 BC

Explanation:

Although various copper tools and decorative items dating back as early as 9000 BCE have been discovered, archaeological evidence suggests that it was the early Mesopotamians who, around 5000 to 6000 years ago, were the first to fully harness the ability to extract and work with copper.

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What will be the new volume if 125 mL of He gas at 100 degree Celsius and .979 atm is cooled to 26 degree Celsius and the pressu

ycow [4]

Use Boyle's Law of Pressure: P1 x V1 = P2 x V2. Givens: P1=0.9 atm V1= 4 P2= 0.9 atm Find: V2 Equation: 0.9 atm x 4 x 4 L = 0.20 atm x V2Solve: 36 atmL= 0.20 atm x V2 18 : = V2 Short answer: The new volume is 104 ml.

6 0

4 years ago

Glucose, C6H12O6,C6H12O6, is used as an energy source by the human body. The overall reaction in the body is described by the eq

Ilia_Sergeevich [38]

Answer:

Mass of oxygen = 61.824 g

Mass of carbon dioxide = 85.01 g

Explanation:

Given data:

Mass of glucose = 58 g

Mass of carbon dioxide = ?

Mass of oxygen = ?

Solution:

First of all we will write the balanced chemical equation,

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Moles of glucose:

Number of moles = mass / molar mass

Number of moles = 58 g/180 g/mol

Number of moles = 0.322 mol

Now we compare the moles of oxygen with glucose from balance chemical equation.

C₆H₁₂O₆ : O₂

1 : 6

0.322 : 0.322×6 = 1.932 mol

Mass of oxygen:

Mass of oxygen = number of moles × molar mass

Mass of oxygen = 1.932 mol × 32 g/mol

Mass of oxygen = 61.824 g

Now we compare the moles of carbon dioxide with moles of glucose and oxygen.

C₆H₁₂O₆ : CO₂

1 : 6

0.322 : 0.322×6 = 1.932 mol

O₂ : CO₂

6 : 6

1.932 : 1.932

Mass of carbon dioxide;

mass of carbon dioxide = number of moles × molar mass

mass of carbon dioxide = 1.932 mol × 44 g/mol

mass of carbon dioxide = 85.01 g

7 0

3 years ago

If 16.29 grams of Na2SO4 is mixed with 3.697 grams of C and allowed to react according to the balanced equation: Na2SO4(aq) + 4

abruzzese [7]

Answer: The limiting reagent in the given chemical reaction is carbon metal.

Explanation:

Excess reagent is defined as the reagent which is present in large amount in a chemical reaction.

Limiting reagent is defined as the reagent which is present in small amount in a chemical reaction. Formation of product depends on the limiting reagent.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)