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3 years ago

Which process is an example of a chemical change?

Chemistry

2 answers:

love history [14]3 years ago

7 0

Answer: A metal railing rusting in damp weather.

Explanation:

A chemical change is one in which a new substance is formed during the process of this change and it's not reversible.

A metal railing rusting in damp weather is an example of a chemical change because a new substance called Rust (Fe2O3) you is formed when iron reacts chemically with air.

Yuliya22 [10]3 years ago

4 0

<span>Chemical Energy is energy stored in the bonds of chemical compounds (atoms and molecules). It is released in a chemical reaction, often producing heat as a by-product (exothermic reaction). Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy.

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2.5 piece of lithium is dropped into a 500 g sample of water at 22.1 C.ten temperature of the water increases to 23.5 C. How muc

Dominik [7]

Answer:

2.6 kJ

Explanation:

The formula for the amount of heat (q) absorbed by the water is

q = mCΔT

1. Calculate ΔT

ΔT = 23.5 °C - 22.1 °C = 1.4 °C

2. Calculate q

q₂ = mCΔT = 500 g × 4.184 J·°C⁻¹g⁻¹ × 1.4 °C = 2900 J = 2.9 kJ

3 0

4 years ago

A 825 g iron block is heated to 352 degrees C and is placed in an insulated container (of negligible heat capacity) containing 4

Stella [2.4K]

Answer : The final equilibrium temperature of the water and iron is, 537.12 K

Explanation :

In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.

$q_1=-q_2$

$m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)$

where,

$c_1$ = specific heat of iron = 560 J/(kg.K)

$c_1$ = specific heat of water = 4186 J/(kg.K)

$m_1$ = mass of iron = 825 g

$m_2$ = mass of water = 40 g

$T_f$ = final temperature of water and iron = ?

$T_1$ = initial temperature of iron = $352^oC=273+352=625K$

$T_2$ = initial temperature of water = $20^oC=273+20=293K$

Now put all the given values in the above formula, we get:

$(825\times 10^{-3}kg)\times 560J/(kg.K)\times (T_f-625K)=-(40\times 10^{-3}kg)\times 4186J/(kg.K)\times (T_f-293K)$

$T_f=537.12K$

Therefore, the final equilibrium temperature of the water and iron is, 537.12 K

8 0

3 years ago

Which two geographic features form as a result of continental-continetal convergent<br> plates?

Kaylis [27]

Answer:

Deep ocean trenches, volcanoes, island arcs, submarine mountain ranges, and fault lines are examples of features that can form along plate tectonic boundaries. Volcanoes are one kind of feature that forms along convergent plate boundaries, where two tectonic plates collide and one moves beneath the other.

Explanation:

I hope it's help u

Please brainiest

5 0

3 years ago

2. When two oppositely charged particles are brought near each other, they produce a torceted the stone

Svetach [21]

Answer:

Explanation:

An unbalanced force is your answer.

8 0

3 years ago

Rank and explain how the freezing point of 0.100 m solutions of the following ionic electrolytes compare. List from lowest freez

Elden [556K]

Answer:

The solutions are listed from the lowest freezing point to highest freezing point.

Mg₃(PO₄)₂ - AlBr₃ - BeBr₂ - KBr

Explanation:

Colligative property of freezing point, is the freezing point depression.

Formula is:

ΔT = Kf . m . i

Where ΔT = T° freezing pure solvent - T° freezing solution

Kf is the cryoscopic constant

m is molality and i is the Van't Hoff factor (number of ions, dissolved in solution)

In this case, T° freezing pure solvent is 0° because it's water, so the Kf is 1.86 °C/m, and m is 0.1 molal.

The i modifies the T° freezing solution. The four salts, are ionic compounds, so for each case:

BeBr₂ → Be²⁺ + 2Br⁻ i = 3

AlBr₃ → Al³⁺ + 3Br⁻ i = 4

Mg₃(PO₄)₂ → 3Mg²⁺ + 2PO₄⁻³ i = 5

KBr → K⁺ + Br⁻ i = 2

Solution of Mg₃(PO₄)₂ will have the lowest temperature of freezing and the solution of KBr, the highest (always lower, than 0°).

8 0

3 years ago