The quantity of heat required to change the temperature of 1 g of a substance by 1°c is defined as

Two 10g blocks, one of copper and one of iron, were heated from 300 K to 400K (a temperature difference of 100 K).

12345 [234]

1) 385 J

2) 450 J

Explanation:

1)

The amount of energy that must be absorbed by a certain substance in order to increase its temperature by $\Delta T$ is given by the equation:

$Q=mC\Delta T$

where

m is the mass of the substance

C is its specific heat capacity

$\Delta T$ is the increase in temperature of the substance

For the block of copper in this problem, we have:

m = 10 g is the mass

$C=0.385 J/gK$ is the specific heat capacity of copper

$\Delta T=400-300 = 100 K$ is the change in temperature

So, the energy absorbed by the block of copper is

$Q=(10)(0.385)(100)=385 J$

2)

Similarly for the block of iron, the energy absorbed by the iron is given by

$Q=mC\Delta T$

where

m is the mass of the block of iron

C is its specific heat capacity of iron

$\Delta T$ is the increase in temperature of the block

Here we have:

m = 10 g is the mass of the block

$C=0.450 J/gK$ is the specific heat capacity of iron

$\Delta T=400-300 = 100 K$ is the change in temperature

So, the energy absorbed by the block of iron is

$Q=(10)(0.450)(100)=450 J$

6 0

2 years ago

What is the formula for the compound made from mercury (II) and the nitrate ion.

Kazeer [188]

Answer:

Hg(NO3)2

Explanation:

Hope it helps! :)

5 0

2 years ago

Read 2 more answers

Draw one line connecting each factor that increases the rate of a

VLD [36.1K]

Answer:

Adding a catalyst - More collisions every second and more collisions with enough energy to break bonds.

Increase in pressure - more collisions every second

Increase in temperature - more collisions every second with enough energy to break bonds

Explanation:

According to the collision theory, chemical reaction occurs as a result of collision between reacting particles. Only particles that possess energy above the activation energy of the reaction can collide and result in product formation. Collision of particles having energy less than the activation energy merely result in elastic collisions.

Adding a catalyst lowers the activation energy of the reaction. If the activation energy is lowered, more reactants collide and more of those collisions now have enough energy to break bonds.

When the temperature is increased, the particles become more energetic hence more collisions with energy to break bonds occur.

Increase in pressure brings the reactant particles into close proximity hence more collisions occur.

4 0

2 years ago

Correct scientific term for a substance that is burned to provide heat?

marishachu [46]

Fuel......................................

3 0

3 years ago

What are the half-reactions for a galvanic cell with Zn and Mg electrodes?

Alona [7]

the half-reactions

cathode : Zn²⁺ (aq) + 2e⁻ ---> Zn (s)

anode : Mg (s) → Mg²⁺ (aq) + 2e−

a balanced cell reaction

Zn²⁺(aq) + Mg(s)→ Zn(s) + Mg²⁺ (aq)

<h3 /><h3>Further explanation</h3>

Given

Zn and Mg electrodes

Required

The half-reactions for a galvanic cell

Solution

To determine the reaction of a voltaic cell, we must determine the metal that serves as the anode and the metal that serves as the cathode.

To determine this, we can either know from the standard potential value of the cell or use the voltaic series

1. voltaic series

The more to the left, the metal is more reactive (easily release electrons) and the stronger reducing agent

So the metal on the left will easily undergo oxidation and function as anode

Since Mg is located to the left of Zn, then Mg functions as anode and Zn as a cathode

2. Standard potentials cell of Mg and Zn metals :

Mg2+ + 2e– → Mg E° = -2,35 V

Zn2+ + 2e– → Zn E° = -0,78 V

The anode has a smaller E°, then Mg is the anode and Zn is the cathode.

7 0

3 years ago