Answer:
The first fossils were marine reptiles called plesiosaurs. They were found on Seymour Island in 1982. The first dinosaur fossil was an ankylosaur, found on James Ross Island in 1986.
Explanation:
Answer is: the third reaction.
Elements in this chemical reaction do not change their oxidation number. Hydrogen has oxydation number +1, sulfur oxidation number is +6, oxygen has oxidation number -2 and barium has +2 on both sides of chemical reaction. In other reactions elements change their oxidation numbers.
Answer:
Answer:
0.027 mole of NaOH.
Explanation:
We'll begin by obtaining the number of mole H2SeO4 in 45mL of 0.30M H2SeO4
This is illustrated below:
Molarity of H2SeO4 = 0.3M
Volume of solution = 45mL = 45/1000 = 0.045L
Mole of H2SeO4 =...?
Mole = Molarity x Volume
Mole of H2SeO4 = 0.3 x 0.045
Mole of H2SeO4 = 0.0135 mole
Next, the balanced equation for the reaction. This is given below:
H2SeO4 + 2NaOH –> Na2SeO4 + 2H2O
From the balanced equation above,
1 mole of H2SeO4 required 2 moles of NaOH.
Therefore, 0.0135 mole of H2SeO4 will require = 0.0135 x 2 = 0.027 mole of NaOH.
Therefore, 0.027 mole of NaOH is needed for the reaction.
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Explanation:
