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3 years ago

Why do scientists use models?

Chemistry

1 answer:

aksik [14]3 years ago

6 0

C. Models help scientists visualize things that they cannot see.

Explanation:

A model is used to help scientists visualize things that they cannot see. A model is used to represent an idea, an object or a process that describes a phenomena. It tends to be thought of a speculation instrument to help structure clarifications.

Models are valuable rearrangements to help understanding. The models are incredible assets however they are legitimate as long as they can clarify the entirety of the accessible information that is from the perceptions and estimations.

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consider the reaction between calcium oxide and carbon dioxide: cao ( s ) + co 2 ( g ) → caco 3 ( s ) a chemist allows 14.4 g of

lana [24]

Answer:

Explanation:

Given data:

Mass of calcium oxide = 14.4 g

Mass of carbon dioxide = 13.8 g

Actual yield of calcium carbonate = 19.4 g

Mass of calcium carbonate produced = ?

Limiting reactant = ?

Percent yield = ?

Chemical equation:

CaO + CO₂ → CaCO₃

Number of moles of CaO:

Number of moles of CaO = Mass /molar mass

Number of moles of CaO = 14.4 g / 56.1g/mol

Number of moles of CaO = 0.26 mol

Number of moles of CO₂:

Number of moles of CO₂= Mass /molar mass

Number of moles of CO₂ = 13.8 g / 44 g/mol

Number of moles of CO₂ = 0.31 mol

Now we will compare the moles of CaCO₃ with CO₂ and CaO.

CaO : CaCO₃

1 : 1

0.26 : 0.26

CO₂ : CaCO₃

1 : 1

0.31 : 0.31

The number of moles of CaCO₃ produced by CaO are less it will be limiting reactant.

Limiting reactant:

CaO

Theoretical yield:

Mass of CaCO₃ = moles × molar mass

Mass of CaCO₃ = 0.26 mol × 100 g/mol

Mass of CaCO₃ = 26 g

Percent yield:

Percent yield = Actual yield / theoretical yield × 100

Percent yield = 19.4 g/ 26 g× 100

Percent yield = 74.6 %

3 0

3 years ago

When sugar is burned, water vapor and carbon dioxide are produced.

Bas_tet [7]

Answer;

12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.

Explanation:

Using a balanced chemical equation we can identify the number of carbon, hydrogen, and oxygen atoms in sugar.

CxHyOn + 12O₂ → 11 H₂O + 12CO₂

When an equation is completely balanced, then the number of each atom of an element is equal on the reactant side and the product side.

Therefore;

For carbon; x = 12

For Hydrogen; y = (11×2) = 22

For Oxygen; n + (12×2) = 11 + (12×2)

= n + 24 = 11 + 24

n = 11

Therefore the sugar has, 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.

Thus the balanced equation would be;

C₁₂H₂₂O₁₁ + 12O₂ → 11 H₂O + 12CO₂

6 0

3 years ago

Read 2 more answers

When solution A was mixed with solution B, the solution turned cloudy, the test tube did not feel warm, and there were no visibl

son4ous [18]

Answer:

Precipitation reaction

Explanation:

Given that solution A was mixed with solution B, the solution turned cloudy. The test is not warm and no bubbles visible. This means that the precipiate is formed.

The concept is when two colourless solutions react to form a cloudy precipitate that settles at bottom of a solution then the reaction is said to be a precipitation reaction.

An example can be the Reaction of Silver nitrate with common salt.

3 0

3 years ago

Calculate ∆h0 for the reaction 2 n2(g) + 5 o2(g) −→ 2 n2o5(g) given the data h2(g) + 1 2 o2(g) −→ h2o(ℓ) ∆h 0 f = −283.7 kj/mol

8_murik_8 [283]

Based on Hess's Law:

2 N2(g) + 6 O2(g) + 2 H2(g) −→ 4 HNO3(l) ∆Hf = (−171.9 kJ/mol)(4 mol) 
2 H2O(l) −→ 2 H2(g) + O2(g) ∆Hf = (-283.8 kJ/mol)(2 mol)(-1) →times -1, rxn is reversed 
4 HNO3(l)−→ 2 N2O5(g) + 2 H2O(l) ∆Hf = (-76.4 kJ/mol)(2 mol)(-1) →times -1, rxn is reversed 

2 N2(g) + 5 O2(g) −→ 2 N2O5(g) ∆H0 = 32.8 kJ

7 0

4 years ago

the presence of which element would indicate that a star is going through a high mass star life cycle as opposed to loe mass sta

love history [14]

If you look on Quizlet it will help you but to save you the hassle the answer is Iron.

4 0

3 years ago

Read 2 more answers