Answer:
.46 moles H2O2
3,014 grams Au
Explanation:
H2O2:
15.78g (1 mol/34g) = .46 moles H2O2
Au:
15.3mol (197g/mol) = 3,014 grams Au
To begin with, the equation given is not correct.
Correct equation is : CaCO3 + HCl ---> CaCl2 + H2O + CO2
It's CaCl2 not CaCl because Ca has a valency of 2
LHS RHS
CaCO3 + HCl ---> CaCl2 + H2O + CO2
First of all, to balance the equation you must look at the number of atoms on each side of the equation.
we have 2 H on the RHS and 1 H on the LHS. So, we put a 2 on the LHS
CaCO3 + 2HCl ---> CaCl2 + H2O + CO2
Check for the LHS: 1 Ca, 1 C, 3 O, 2 H & 2 Cl on the LHS
Now check for the RHS: 1 Ca, 2 Cl, 2 H, 1 C & 3 O
Hope it helped!
Answer:
0.727 l.
Explanation:
For the new dilute Sulphuric acid,
Number of moles = molar concentration × volume
= 2.5 × 5
= 12.5 mol
Volume of concentrated solution = 12.5/17.2
= 0.727 l of 17.2 M of sulphuric acid to be diluted.
Answer: The element shown in the image is Helium (He).
Explanation: We are given a image of an atom having protons, neutrons and electrons.
Number of protons as shown in image = 2
Number of neutrons as shown in image = 2
Number of electron as shown in image = 2
Atomic number = Number of protons = Number of electrons
Atomic number of the element = 2
Atomic Mass = Number of protons + Number of neutrons
Atomic mass = 2 + 2 = 4
The element having Atomic number = 2 and mass number = 4 is Helium.
Element =