The state of matter that is able to be compressed is gas liquid solid

Which of the following is an example of a physical change? A) grinding coffee beans B) baking a cake C) converting water to hydr

lara [203]

Answer: A) grinding coffee beans

Explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.

1. Grinding coffee : Only change in size takes place, thus a physical change

2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.

3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change

4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.

5 0

2 years ago

4 points

Ilya [14]

The vertical columns are groups

The horizontal rows are periods

4 0

3 years ago

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Manganese commonly occurs in nature as a mineral. The extraction of manganese from the carbonite mineral rhodochrosite, involves

hjlf

This is an incomplete question, here is a complete question.

Manganese commonly occurs in nature as a mineral. The extraction of manganese from the carbonite mineral rhodochrosite, involves a two-step process. In the first step, manganese (II) carbonate and oxygen react to form manganese (IV) oxide and carbon dioxide:

$2MnCO_3(s)+O_2(g)\rightarrow 2MnO_2(s)+2CO_2(g)$

In the second step, manganese (IV) oxide and aluminum react to form manganese and aluminum oxide:

$3MnO_2(s)+4Al(s)\rightarrow 3Mn(s)+2Al_2O_3(s)$

Write the net chemical equation for the production of manganese from manganese (II) carbonate, oxygen and aluminum. Be sure your equation is balanced.

Answer : The net chemical equation for the production of manganese is:

$6MnCO_3(s)+3O_2(g)+8Al(s)\rightarrow 6CO_2(g)+6Mn(s)+4Al_2O_3(s)$

Explanation :

The given two chemical reactions are:

(1) $2MnCO_3(s)+O_2(g)\rightarrow 2MnO_2(s)+2CO_2(g)$

(2) $3MnO_2(s)+4Al(s)\rightarrow 3Mn(s)+2Al_2O_3(s)$

First we are multiplying reaction 1 by 3, and reaction 2 by 2, we get:

(1)

(2) $6MnO_2(s)+8Al(s)\rightarrow 6Mn(s)+4Al_2O_3(s)$

Now we are adding both the reactions, we get the overall chemical reaction.

$6MnCO_3(s)+3O_2(g)+6MnO_2(s)+8Al(s)\rightarrow 6MnO_2(s)+6CO_2(g)+6Mn(s)+4Al_2O_3(s)$

The $MnO_2$ is common on both side, by cancelling it, we get:

The net chemical equation for the production of manganese is:

$6MnCO_3(s)+3O_2(g)+8Al(s)\rightarrow 6CO_2(g)+6Mn(s)+4Al_2O_3(s)$

5 0

3 years ago

How many joules of heat are required to raise the temperature of 320.0 grams of water from 24.2°C to 50.8°C? Heat capacity of wa

balu736 [363]

Answer:

35750.4 Joules

Explanation:

Using the formula as follows;

Q = m × c × ∆T

Where;

Q = amount of heat (joules)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

According to the provided information,

mass (m) = 320.0 grams

c = 4.2 J/g°C

∆T = (50.8°C - 24.2°C) = 26.6°C

Q = ?

Using; Q = m × c × ∆T

Q = 320 × 4.2 × 26.6

Q = 35750.4 J

5 0

3 years ago

The half-cell is a chamber in the voltaic cell where one half-cell is the site of the oxidation reaction and the other half-cell

marysya [2.9K]

Answer:

$\boxed{\rm \text{Fe(s) $\rightleftharpoons$ Fe$^{2+}$(aq) + 2e$^{-}$}}$

Explanation:

The half-cell reduction potentials are

Ag⁺(aq) + e⁻ ⇌ Ag(s) E° = 0.7996 V

Fe²⁺(aq) + 2e⁻ ⇌ Fe(s) E° = -0.447 V

To create a spontaneous voltaic cell, we reverse the half-reaction with the more negative half-cell potential.

The anode is the electrode at which oxidation occurs.

The equation for the oxidation half-reaction is

$\boxed{\rm \textbf{Fe(s) $\rightleftharpoons$ Fe$^{2+}$(aq) + 2e$^{-}$}}$

4 0

3 years ago