Answer:
Explanation: ques 8
I think so it is a hydrogen atom ,because it is only atom atom that has 1 proton .as the question is to identify the atom with no of proton so it is hydrogen . it has atomic number 1
ques 9
the isotpoe of hydrogen having 2 neutrons is caled tritrium . it has mass number 3
ques no 10
as the protons are present in nucleus and electrons revovle around it so the term is clear . remember atoms do not have defined boundaries .
Answer:
a. alkali
b. chemical
c. reactants
d. neutralised, acid
e. neutralisation
f. products
Explanation:
hope this helps and sorry if it is not right :)
Answer:
Diversification and adaptive radiation.
Explanation:
Answer:
125 L of 15% and 265.625 L of 65% HCl
Explanation:
let x = volume of 15% HCl, y = 65% HCl
15x + 65y = 49 × 390.625
15x + 65y = 19140.625
x + y = 390.625
x = 390.625 - y
substitute for x in equation 1
15 (390.625 - y) + 65y = 19140.625
5859.375 - 15 y + 65 y = 19140.625
50 y = 19140.625 - 5859.375 = 13281.25
y = 132181.25 / 50 = 265.625 L
X = 390.625 - y = 390.625 - 265.625 = 125 L
Answer:
-177.9 kJ.
Explanation:
Use Hess's law. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2Ca(s) + O2(g) → 2CaO(s) ΔH = -1269.8 kJ We need to get rid of the Ca and O2 in the equations, so we need to change the equations so that they're on both sides so they "cancel" out, similar to a system of equations. I changed the second equation. Ca(s) + CO2(g) + 1/2O2(g) → CaCO3(s) ΔH = -812.8 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ The sign changes in the second equation above since the reaction changed direction. Next, we need to multiply the first equation by two in order to get the coefficients of the Ca and O2 to match those in the second equation. We also multiply the enthalpy of the first equation by 2. 2Ca(s) + 2CO2(g) + O2(g) → 2CaCO3(s) ΔH = -1625.6 kJ 2CaO(s) → 2Ca(s) + O2(g) ΔH = +1269.8 kJ Now we add the two equations. The O2 and 2Ca "cancel" since they're on opposite sides of the arrow. Think of it more mathematically. We add the two enthalpies and get 2CaO(s) + 2CO2(g) → 2CaCO3(s) and ΔH = -355.8 kJ. Finally divide by two to get the given equation: CaO(s) + CO2(g) → CaCO3(s) and ΔH = -177.9 kJ.