Answer:- Mass of the alloy is 2.8 kg.
Solution:- Mass of Cr in the alloy is 325 g and mass of Fe in the alloy is 2.5 kg. Mass of alloy would be the sum of masses of constituent metals.
Masses of the metals are not in the same units. So, we need to make the units equal. The want answer in kg so let's convert mass of Cr from g to kg.
Since, 1000 g = 1 kg
So, 
= 0.325 kg
Mass of alloy = mass of Cr + mass of Fe
mass of alloy = 0.325 kg + 2.5 kg = 2.825 kg
If we consider significant figures then as per the rules, the answer should not have more than one decimal place.
So, 2.825 kg is round off to 2.8 kg and hence the mass of the alloy is 2.8 kg.
Answer:
7.941
Explanation:
You can look at a picture of the periodic table.To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons. Example: Find the atomic mass of an isotope of carbon that has 7 neutrons. You can see from the periodic table that carbon has an atomic number of 6, which is its number of protons.
Hope I helped
Conductivity, malleability, and high melting points. Hope this helps :)
Molar mass of 13c = 13 grams
number of moles = mass / molar mass
therefore,
number of moles = 7 / 13
To know the number of atoms in 7/13 moles, we simply multiply the number of moles by Avogadro's number as follows:
number of atoms = (7/13) x 6.022 x 10^23 = 3.2426 x 10^23 atoms
In balancing reactions, the number of atoms on each side should be of equal number. It is the most important rule in reactions. Also, we should know the correct substances involved in the reaction. We do as follows:
2K + MgBr2 = 2KBr + Mg