An atom is determine to have 17 protons, 18 electrons, and 18 neutrons. What are the mass number and charge of this atom or ion
1 answer:
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Answer:
<em><u>The molarity of the CoBr2•4H2O solution is 7.64 × 10-2 M</u></em>
Explanation:
Cobalt (II) bromide tetrahydrate
• Cobalt - A transition metal with Roman numeral (II) → charge: +2 → Co2+
• Bromide - anion from group 7A → -1 charge → symbol: Br-
• Tetrahydrate- tetra- means 4 and hydrate is H2O
The chemical formula of the compound is: CoBr2•4H2O
We then need to determine the number of moles of CoBr2•4H2O since this is the only information missing for us to find molarity. Notice that the volume of the solution is already given.
We’re given the mass of CoBr2•4H2O. We can use the molar mass of CoBr2•4H2O4 to find the moles.
•The molar mass of CoBr2•4H2O is:
CoBr2•4H2O
1 Co x 58.93 g/mol Co = 58.93 g/mol
2 Br x 79.90 g/mol Br = 159.80 g/mol
8 H x 1.008 g/mol H = 8.064 g/mol
4 O x 16.00 g/mol O = 64.00 g/mol
________________________________________
Sum = <u>290.79 g/ mo</u>
The moles of CoBr2•4H2O is:
= 10.0 g CoBr2•4H2O x
= <u>0.0344 mol CoBr2•4H</u>
We know that the volume of the solution is 450 mL.
We can now calculate for molarity:
Convert mL to L → 1 mL = 10-3 L
Formula:
Molarity (M)= Mole of solute / Liters of solution
= 0.0344 mol CoBr2•4H / 450 mL x 1 ml / 10^ -3 L
= 0.0764
= 7.64 × 10-2 mol/L
Answer:
The number 10,847,100 in Scientific Notation is
Explanation:
Scientific notation is an easy form to write long numbers and it is commonly used in the scientific field. To write a long number in a shorter way it is necessary to 'move' the decimal point to the left the number of positions that are necessary until you get a unit. Then you write the number and multiplied it by 10 raised to the number of positions you moved the decimal point. In this case, it is necessary to move the decimal point 7 positions so, we multiply the number by 10 raised to 7.