Answer:
7. 4H₂O
Elements: Hydrogen, Oxygen
Number of molecules: 4
Number of elements: 8 H, 4 O
Number of Atoms: 12
Explanation:
The elements are determined by the their symbol i.e. H = hydrogen.
The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).
The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1. 4H₂ = 4x2 = 8; 4O = 4x1 = 4.
The number of atoms is all the individual elements added together. 8+4 = 12.
Answer:
1 and 3
Explanation:
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
Answer:
18.0 Ampere is the size of electric current that must flow.
Explanation:
Moles of electron , n = 550 mmol = 0.550 mol
1 mmol = 0.001 mol
Number of electrons = N
Charge on N electrons : Q
Duration of time charge allowed to pass = T = 49.0 min = 49.0 × 60 seconds
1 min = 60 seconds
Size of current : I
18.0 Ampere is the size of electric current that must flow.
Answer:
5.0 × 10²⁴ molecules
Explanation:
Step 1: Write the balanced double displacement reaction
2 NaOH + CuSO₄ ⇒ Na₂SO₄ + Cu(OH)₂
Step 2: Calculate the moles corresponding to 5.0 × 10²⁴ molecules of Na₂SO₄
We will use Avogadro's number: there are 6.02 × 10²³ molecules in 1 mole of molecules.
5.0 × 10²⁴ molecule × 1 mol/6.02 × 10²³ molecule = 8.3 mol
Step 3: Calculate the moles of CuSO₄ required to produce 8.3 moles of Na₂SO₄
The molar ratio of CuSO₄ to Na₂SO₄ is 1:1. The moles of CuSO₄ required are 1/1 × 8.3 mol = 8.3 mol.
Step 4: Calculate the molecules corresponding to 8.3 moles of CuSO₄
We will use Avogadro's number.
8.3 mol × 6.02 × 10²³ molecule/1 mol = 5.0 × 10²⁴ molecule
Answer:
The answer to your question is 25.2 g of acetic acid.
Explanation:
Data
[Acetic acid] = 0.839 M
Volume = 0.5 L
Molecular weight = 60.05 g/mol
Process
1.- Calculate the number of moles of acetic acid
Molarity = moles / volume
-Solve for moles
moles = Molarity x volume
-Substitution
moles = (0.839)(0.5)
-Result
moles = 0.4195
2.- Calculate the mass of acetic acid using proportions and cross multiplications
60.05 g ----------------------- 1 mol
x ----------------------- 0.4195 moles
x = (0.4195 x 60.05) / 1
x = 25.19 g
3.- Conclusion
25.2 g are needed to prepare 0.500 L of Acetic acid 0.839M
