Answer:
The answer is 1.06g.
Explanation:
Analysis of question:
1. Identify the information in the question given.
- volume of HCl is 2 dm3
- pH of HCl is 2.0
2. What the question want?
- mass of Na2CO3 is ?(unknown)
- 3. Do calculation.
- 1st-Write a balanced chemical equation:
Na2CO3 + 2HCl (arrow) 2NaCl + H20 + CO2
- 2nd-Determine the molarity of HCl with the value of 2.0.
pH= -log[H+]
2.0= -log[H+]
log[H+]= -2.0
[H+]= 10 to the power of negative 2(10-2)
=0.01 mol dm-3
molarity of HCl is 0.01 mol dm-3
- 3rd-Find the number of moles of HCl
n=MV
=0.01 mol dm-3 × 2 dm3
=0.02 mol of HCl
- 4th-Find the second mol of it.
Based on the chemical equation,
2.0 mol of HCl reacts with 1.0 mol of Na2CO3
0.02 mol of HCl reacts with 0.01 mol of Na2CO3
<u>N</u><u>a</u>2CO3>a=<u>1</u><u> </u>mol
<u>2</u><u>H</u>Cl>b=<u>2</u><u> </u>mol
mass= number of mole × molar mass
g=0.01 × [2(23)+ 12+ 3(16)]
g=0.01 × 106
# =1.06 g.
Answer:
C. The theory that states that all molecules are constantly moving
Explanation:
The Kinetic Molecular Theory states that all molecules are constantly moving.
A and B are wrong. There are no such theories.
D is wrong. Modern atomic theory describes the energy levels of electrons.
Answer: Among the listed substances is the molecular compound.
Explanation:
A chemical compound formed by the chemical combination of two or more non-metals is called a molecular compound or covalent compound.
For example, Xe and Cl are non-metals. The compound formed by them is which is a molecular compound.
A molecular compound is formed by sharing of atoms between the combining atoms.
Whereas NaF, and CaO are all ionic compounds as they are formed by chemical combination of a metal and a non-metal.
Thus, we can conclude that among the listed substances is the molecular compound.
Answer: approximately 15.1 grams.
Explanation: The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want. Change 25 grams of potassium chlorate to moles. Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron. 1 K x 39 grams/mole+1 Cl x 35.4grams/ mole+3 O x 16 grams/ mole = 122.4 grams / mole Potassium Chlorate 25 122.4 = moles. 2.05 moles of Potassium Chlorate. There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride. 2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride. Find the gram molecular mass of Potassium Chloride. 1 K x 39 = 39+1 Cl x 35.4 = 35.4 = 74.4 grams / mole. 2.05 moles x 74.4 grams/ mole = 15.2 grams