The number of grams of NaOH that are needed to make 500 ml of 2.5 M NaOH solution
calculate the number of moles =molarity x volume/1000
= 2.5 x 500/1000 = 1.25 moles
mass = moles x molar mass of NaOH
= 1.25 x40= 50 grams of NaOH
Answer:
about 79% (79.04369332 to be exact)
Explanation:
Percent composition=(Molar mass of element x amount of it)/Molar mass of compound x 100
Br= 3 x 79.9/303.25 x100=79.04369332
3. Cl₂ + 2KI --> 2KCl + I₂
Cl = 2 Cl = 2
K = 2 K = 2
I = 2 I = 2
4. 2NaCl --> 2Na + Cl₂
Na = 2 Na = 2
Cl = 2 Cl = 2
5. 4Na + O₂ --> 2Na₂O
Na = 4 Na = 4
O = 2 O = 2
6. 2Na + 2HCl --> H₂ + 2NaCl
Na = 2 Na = 2
H = 2 H = 2
Cl = 2 Cl = 2
7. 2K + Cl₂ --> 2KCl
K = 2 K = 2
Cl = 2 Cl = 2
I think your answer would be an Atom because it is referred to as the smallest unit of matter that retains the chemical properties of an element.
I Hope my answer help you :)
