The answer is the 3rd choice
Answer: The density of the material is 2.66 g/mL and it is likely this is made of Aluminum
Explanation:
The first step to know the material of the chunk of metal is to calculate its density. The general formula for density is P (density) =
. Moreover, in this case, it is known the mass is 37.28 g, but the volume is not directly provided. However, we know the water in the graduated cylinder had a volume of 20.0 mL and this increased to 34.0 mL when the chunk of metal is added, this means the volume of the metal is 14 mL (34.0 mL - 20.0 mL = 14 mL). Now let's calculate the density:

This means the density of this metal is 2.66 g/mL, which can be rounded as 2. 7 g/mL, and according to the chart, this is the density of aluminum. Therefore, this material of this chunk is aluminum.
Answer:
Death rates, Birth rates, and immigration rates
Explanation:
For the first one.. the Reactant side is Zn+2HCl produces Zncl2 and H2... and it is balanced too
0.20 moles of iron will be formed in the reaction.
Explanation:
The balanced chemical equation for the reaction between iron (iii) oxide and carbon monoxide to form Fe is to be known first.
the balanced reaction is :
Fe2O3 + 3CO⇒ 2 Fe + 3 CO2
so from the data given the number of moles of carbon monoxide can be known:
3 moles of CO reacted with Fe2O3 to form 2 moles of iron in the reaction.
Number of moles of CO is 6.20 moles
11.6 gm of iron is formed
so the number of moles of iron formed is calculated as
n = mass of iron ÷ atomic weight of iron
= 11.6 ÷ 55.84
= 0.20 moles of iron will be formed when 11.6 gram of iron is produced.