Answer:
all the statements are true of chemical changes
A. actinides do not occur in nature.
Answer:
See explanation
Explanation:
The balanced redox reaction equation is;
8H+ + MnO4^- + 5Fe2+ ---------> Mn2+ + 5Fe3+ + 4H2O
Amount of KMnO4 reacted = 31.60/1000 * 0.05120 = 1.62 * 10^-3 moles
From the reaction equation;
1 mole of MnO4^- reacted with 5 moles of Fe2+
1.62 * 10^-3 moles will react with 1.62 * 10^-3 moles * 5/1 = 8.1 * 10^-3 moles
Mass of Fe2+ reacted = 8.1 * 10^-3 moles * 56 g/mol
Mass of Fe2+ reacted = 0.45 g
Amount of iron in the sample = 0.45 g
Percentage of iron in the sample;
0.45 g/4.230 g * 100 = 10.6 %
Weathering of the rock and sedimentation are decomposition processes. Through time, the minerals in the rocks soften due to pressure and heat. So, they crumble down and reduce in terms of size. Once they do, they become sand or part of the soil. So, the answer is A.
Answer:
1. 505g is the mass of the aluminium.
2. The answer is in the explanation
Explanation:
1. To solve this question we need to find the volume of the rectangle. With the volume and density we can find the mass of the solid:
Volume = 7.45cm*4.78cm*5.25cm
Volume = 187cm³
Mass:
187cm³ * (2.702g/cm³) = 505g is the mass of the aluminium
2. When the temperature of a liquid increases, the volume increases doing the density decreases because density is inversely proportional to volume. And works in the same way for gases because the temperature produce more collisions and the increasing in volume.
