D) during chemical reactions the number and types of atoms
A hydrocarbon has only hydrogen and carbon in it. the 1st, 3rd and 4th option all include Oxygen so the only hydrocarbon is option 2
Answer: See below
Explanation:
1. To calculate the mass, you know you can convert by using molar mass. Since mass is in grams, we can use molar mass to convert moles to grams. This calls for the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We manipulate the equation so that we are solving for moles, then convert moles to grams.
n=PV/RT
P= 100 kPa
V= 0.831 L
R= 8.31 kPa*L/mol*K
T= 27°C+273= 300 K
Now that we have our values listed, we can plug in to find moles.


We use the molar mass of NO₂ to find grams.

The mass is 1.52 g.
2. To calculate the temperature, we need to use the Ideal Gas Law.
Ideal Gas Law: PV=nRT
We can manipulate the equation so that we are solving for temperature.
T=PV/nR
P= 700.0 kPa
V= 33.2 L
R= 8.31 kPa*L/mol*K
n= 70 mol
Now that we have our values, we can plug in and solve for temperature.


The temperature is 40 K.
The correct answer is (B) Adding a dilute solution of HCl
<u>EXPLANATION</u>
The presence of carbonate ions can be tested by adding a dilute acid to the solution. The acid displaces Carbon (IV) oxide from the solution. Using HCl, and a carbonate of metal X.
XCO₃₍s₎ + 2HCl₍aq₎⇒ XCl₂₍aq₎+ H₂O₍l₎ + CO₂₍g₎
The gas produced is tested using calcium hydroxide to confirm whether it is carbon (IV) oxide.
Answer:
will be 90054 J
Explanation:
Number of moles = (mass)/(molar mass)
Molar mass of
= 134.45 g/mol
So, 1.00 g of
=
of
= 0.00744 mol of 
0.00744 mol of
produces 670 J of heat
So, 1 mol of
produces
of heat or 90054 J of heat