Answer:c which is 70
Explanation:
i took the test and got it right
An element is a pure substance made up of only one kind of atom. An element is composed of atoms in which it is composed of neutrons and protons. The nucleus is surrounded by electrons. The answer to this problem is A. element
Answer: 2 moles
Explanation:
STP is Standard Temperature and Pressure. That means the pressure is 1.00 atm and the temperature is 273K. Since the oxygen is placed in the same container, we can use Ideal Gas Law to figure out what container the CO₂ used.
Ideal Gas Law: PV=nRT
P=1.00 atm
n=moles
R=0.08206 Latm/Kmol
T=273K
CO₂



Since we know that CO₂ has a 44.8 L container, we can use that to find the moles of oxygen.



There are 2 mol of oxygen.
<span>H2O2
First, let's determine how many moles of hydrogen and oxygen atoms we have. Start by looking up the atomic weights of those elements:
Atomic weight hydrogen = 1.00794
Atomic weight oxygen = 15.999
Moles hydrogen = 1.33 g / 1.00794 g/mol = 1.319522987 mol
Moles oxygen = 21.3 g / 15.999 g/mol = 1.331333208 mol
We now have a ratio of 1.319522987 : 1.331333208 and we want a ratio of small integers that is close. Start by dividing all the numbers in the ratio by the smallest value, giving:
1 : 1.008950371
This ratio is acceptably close to 1:1 so I assume the formula is of the form HnOn where n is a small integer. Let's initially assume that n is 1, so the mass would be
1.00794 + 15.999 = 17.00694
Obviously 17 is far smaller than 34.1. So let's divide 34.1 by 17.00694 and see what n should be:
34.1 / 17.00694 = 2.005063815
So the formula we want is H2O2, which is hydrogen peroxide.</span>