The balanced equation for the reaction between calcium and water to produce calcium hydroxide and hydrogen is

At the beginning of the experiment, the aspirin pill contains 325 mg of acetylsalicylic acid and weighs 400 mg. at the end of ex

Feliz [49]

That would be (110/ 325) * 100

= 33.85 %

8 0

3 years ago

Given these reactions, X ( s ) + 1 2 O 2 ( g ) ⟶ XO ( s ) Δ H = − 668.5 k J / m o l XCO 3 ( s ) ⟶ XO ( s ) + CO 2 ( g ) Δ H = +

qwelly [4]

Answer: The $\Delta H^o_{rxn}$ for the reaction is -1052.8 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The given chemical reaction follows:

$X(s)+\frac{1}{2}O_2(g)+CO_2(g)\rightarrow XCO_3(s)$ $\Delta H^o_{rxn}=?$

The intermediate balanced chemical reaction are:

(1) $X(s)+\frac{1}{2}O_2(g)\rightarrow XO(s)$ $\Delta H_1=-668.5kJ$

(2) $XCO_3(s)\rightarrow XO(s)+CO_2$ $\Delta H_2=+384.3kJ$

The expression for enthalpy of the reaction follows:

$\Delta H^o_{rxn}=[1\times \Delta H_1]+[1\times (-\Delta H_2)]$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(1\times (-668.5))+(1\times (-384.3))=-1052.8kJ$

Hence, the $\Delta H^o_{rxn}$ for the reaction is -1052.8 kJ.

7 0

3 years ago

PLEASE HELP ME WITH A COUPLE OF QUESTIONS!!! Thank You :)

Brrunno [24]

Hey there!

1. A chemical reaction is, B). Any time different substances combine to form a new substance, or when a substance breaks up into different substances

2. Balancing chemical equations is called, C). Equivalentry

3. Sulfuric acid is made of two hydrogen atoms (H), one sulfur atom (5), and four oxygen atoms (0). What is its formula? C). H2S04

Hope this helps!

-Much love, Makayla

5 0

3 years ago

Will give brainlist!!!

alina1380 [7]

Answer:

C

Explanation:

75 mile shallow flat area just off coastlines

8 0

3 years ago

Can someone tell me how to differentiate if a given salt is acidic, basic, or neutral?

satela [25.4K]

$\bold{\huge{\underline{ Solution }}}$

<h3>Basic Characteristic of acids </h3>

Acids are sour in taste
Acid turns blue litmus paper or solution into red litmus paper or solution
Acids are good conductor of electricity because it dissociate into cation in aqueous solution
Acids classified into edible acids and non edible acids. Non edible acids are very hazardous
Generally, All acids are soluble in water
Acids have PH smaller than 7

Arrhenius definition of acids :-

According to Arrehinus,

Acids are those substances which when dissolve in water given H positive ions . Then, this hydrogen ions combine with water to form H30 + ions

Second definition of Acids was given by Bonsted Lowry :-

According to Bonsted Lowry

Acids are the proton donors that is when acids dissociate into water gives hydrogen ions that is H+ ions

3rd definition was given by Lewis 

According to Lewis

Acids are those substances which have the ability to accept a pair of electrons .

Example of Acids

HNO3 :- Nitric acid
H2SO4 :- Sulfuric acid
HCl :- Hydrochloric acid

<h3>Basic characterists of bases </h3>

Bases are bitter in taste
Bases turns red litmus paper into blue litmus paper or solution
Bases are also good conductor of electricity because on dissociation it produces anion in aqueous solution
Bases are also good conductor of electricity
When bases are soluble in water then they are known as alkaline base
Bases have PH greater than 7

Arrehinus definition of bases :-

According to Arrehinus ,

Bases are those substances which when dissolve in water produce OH negative ions that is hydroxide ions

Bonsted Lowry definition 

According to Bonsted Lowry

Bases are the proton donors as they produce OH negative ions in dissociation in aqueous solution

Lewis definition 

According to Lewis

Acids are those substances which have the ability to lose electrons that is they are electron donors.

Example of bases

Ca(OH)2 :- Calcium hydroxide
NaOH :- Sodium hydroxide
KOH :- Potassium hydroxide

[ Note :- There are so many Lewis acids and bases but they are not Arrhenius or Lowry acids or bases ]

<h3>Basic characteristic of salt </h3>

Salts are the ionic compounds which are composed of acids and bases that cation and anion
Salts are generally found in oceans and seas in the forms of crystals
As they are composed of acids and bases so they are neutral in nature but the salt of strong acid or weak base is acidic in nature or vice versa
Salts are also good conductor of electricity as they form ionic bond
Generally, All salts are soluble in water.
The PH of common Salt is 7

Example of salts

NH4Cl :- Ammonium chloride
CuSO4 :- Copper sulphate
NaCl :- Sodium chloride

6 0

2 years ago