Answer:
They are used because of preference or convenience, not necessity. These scales came about historically when there were no standards to calibrate a thermometer against. The Fahrenheit scale used the temperature of the coldest thing then known for its zero, which was salty ice.13-Oct-2019
The statement is false as 85675 grams of nitrogen dioxide is produced instead of 20 grams.
Explanation:
Balance equation for the reaction:
2NO +
⇒ 2N
Data given:
mass of nitrogen produced = 20 gram
mass of oxygen = 29.8 litres or 29800 grams
0xygen is the limiting reagent so,
number of moles of oxygen: (atomic mass of 1 mole 32 grams/mole
number of moles = 
putting the values in the equation:
= 
= 931.5 moles
1 mole of oxygen reacts to give 2 moles of NO2
931.5 moles of oxygen will give x moles
=
1862.5 moles of NO2 produced
in grams
mass = number of moles x atomic mass
mass = 1862.5 x 46.00
= 85675 grams
The statement is false as 85675 grams of nitrogen dioxide is produced instead of 20 grams as said in question.
Answer:
-66.88KJ/mol
Explanation:
It is possible to obtain the heat involved in a reaction using a calorimeter. Formula is:
q = -C×m×ΔT
<em>Where q is heat of reaction, C is specific heat capacity (4.18J/°Cg), m is mass of solution (100.0g) and ΔT is temperature change (23.40°C-22.60°C = 0.80°C)</em>
Replacing:
q = -4.18J/°Cg×100.0g×0.80°C
q = -334.4J
Now, in the reaction:
Ag⁺ + Cl⁻→ AgCl
<em>AgNO₃ as source of Ag⁺ and HCl as source of Cl⁻</em>
Moles that react are:
0.050L× (0.100mol /L) = 0.0050moles
If 0.0050 moles produce -334.4J. Heat of reaction is:
-334.4J / 0.0050moles = -66880J/mol = <em>-66.88KJ/mol</em>
Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.




Here manganese is having an oxidation state of +4 called as cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give
which written in simplest whole number ratios to give neutral 
W*V i believe because it comes down to this :
I is the current, W is wattage V is volts and the * is the thing that represents the Amperes (i’m not 100% but this is my best)