Homogeneous mixture<span>steel
</span>element<span>sodium
</span>mixture, homogeneous<span>brass
</span>
First compute the number of grams of manganese metal required to make 21.7 grams of H2.
21.7 g H2 x (1 mole H2/ 2 g H2) x (1 mole Mn/1 mol H2) x (55 grams Mn/1 mol Mn) = 596.75 grams
Now density = mass/volume
7.43 = 596.75/volume
volume = 596.75/7.43 = 80.31 mL
80.31 mL is the amount of manganese needed.
Answer:
Explanation:
We are asked to find the density of a metal. Density is the mass per unit volume. It is calculated by dividing the mass by the volume.
The mass of the metal sample is 24.64 grams and the volume is 5.91 milliliters. We can substitute these values into the formula.
Divide.
The mass measurement has 4 significant figures the volume measurement has 3 significant figures. Our answer for density must match the least number of significant figures, which is 3.
For the number we calculated, that is the hundredth place. The 9 in the thousandth place tells us to round the 6 up to a 7.
The density of this metal is approximately <u>4.17 grams per milliliter.</u>
Physical and chemical changes are the property of the reactions. The best observation evident of the chemical change is the deposition of the brown crust over the marshmallow.
<h3>What is a chemical change?</h3>
A chemical change is a change that results in the formation of a new substance that cannot be changed back into its original form. They are irreversible and include decomposition, combination, and addition reactions.
The color change of the marshmallow from white to brown shows the chemical change that cannot be reversed back to the original form while the melting of the candle and heating of the metallic fork are physical changes.
Therefore, the burning of marshmallows is a chemical change.
Learn more about chemical change here:
brainly.com/question/2268111
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