Answer:
A) yes
B) The average mass of 12 pennies should be expressed as
( 3.131 + 3.129 + -------- X12 ) g / 12
where X12 = is the mass of the 12th penny
Explanation:
A) I think the the Bureau of Mint changed the way it made pennies because from the experiment and observation carried out on 15 different pennies it can be seen that they had different weights and this difference is associated with the period/time of production of the different pennies,
B ) The average mass of any object should be expressed in the si unit of mass and not having ($) sign attached to the value instead it should be expressed in grams or kilograms (s.i unit of mass )
The average mass of 12 pennies should be expressed as
( 3.131 + 3.129 + -------- X12 ) g / 12
where X12 = is the mass of the 12th penny
<u>Answer:</u> The correct answer is Option B.
<u>Explanation:</u>
Decomposition is a type of chemical reaction in which larger compound breaks down into two or more smaller compounds.

Double displacement reactions is defined as the chemical reaction in which exchange of ions takes place.

Synthesis reaction is a type of reaction in which two or more smaller compounds combines to form a single large compound.

Single displacement reaction is a type of reaction in which a more reactive metal displaces a less reactive metal from its chemical reaction.

In stomach, an acid is present known as hydrochloric acid and to neutralize its effect, antacid is taken which has
as a component.
The reaction between HCl and
is a type of neutralization reaction and it is a type of double displacement reaction.
The equation between the two follows:

Hence, the correct answer is Option B.
<u>Answer:</u> The molality of the solution is 0.1 m.
<u>Explanation:</u>
To calculate the molality of solution, we use the equation:

Where,
= Given mass of solute = 27.1 g
= Molar mass of solute = 27.1 g/mol
= Mass of solvent = 100 g
Putting values in above equation, we get:

Hence, the molality of the solution is 0.1 m.