Answer:
c. 20.0332 g to 20,0 g
Explanation:
A significant figure is each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first non-zero digit, with the exception of the trailing zeros.
<em>Which of the following examples illustrates a number that is correctly rounded to three significant figures?
</em>
a. 109 526 g to 109 500 g. NO. The rounded number has 4 significant figures: 109 500.
b. 0.03954 g to 0.040 g. NO. The rounded number has 2 significant figures: 0.040.
c. 20.0332 g to 20.0 g. YES. The rounded number has 3 significant figures: 20.0.
d. 04.05438 g to 4.054 g. NO. The rounded number has 4 significant figures: 4.054.
e. 103.692 g to 103.7g. NO. The rounded number has 4 significant figures: 103.7.
Answer:
molecules, elements
Explanation:
molecules are a mix of elements
Answer:
12 atm
Explanation:
First, let us convert Celcius into Kelvin: 28.0 °C = 301.15 K and 129.0 °C = 402.15 K
For this question we must employ the Combined Gas Law: 
, where 
is the initial pressure and 
is the new pressure.
We know that intitially, P=9 atm, V=30 L, and T=301.15K. From our problem, only temperature and pressure changes, while the number of moles, volume and the gas constant, R, stay the same, so they are irrelevant.
Thus, the filled out Combined Gas Law would be:
=
, where the volume, moles of gas, and R are cancelled out.
We can manipulate this equation to derive the new pressure. We find that
9atm≈0.74885.
This means that
≈9/0.74885≈12 atm
Answer:
<h3>The answer is 2.0 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 4 g
volume = 2 cm³
We have
We have the final answer as
<h3>2.0 g/cm³</h3>
Hope this helps you
Answer:
option A = C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
Explanation:
Law of conservation of mass:
This law stated that mass can not be created or destroyed in chemical reaction. It just changed from one to another form.
For example:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
28 g + 96 g = 88 g + 36 g
124 g = 124 g
This reaction correctly hold the law of conservation of mass.
Other options:
C + 4H₂ → CH₄
12 g + 8g = 16 g
20 g = 16 g
This reaction do not hold the law of conservation of mass.
3H₂O → 3H₂ + 3O₂
54 g = 6 g + 96 g
54 g = 102 g
This reaction do not hold the law of conservation of mass.
2Na + Cl → NaCl
46 g + 35.5 g = 58.5 g
81.5 g = 58.5 g
This reaction do not hold the law of conservation of mass.
