Heat energy released here
Q = mass x specific heat capacity of water x deltaT
= 25.0 x 4.184 x (-10.0)
= - 1046 Joules
1046 Joules of heat energy is released in this process.
Physical change means - a change from one state ( solid,liquid or gas) to another state without change in chemical composition.
mesozoic era - age of the dinosaurs
end of the paleozoic era - most of earth a desert
end of the mesozoic era - a layer of iridium deposited all over earth
Answer:
1.2 × 10^22 atoms.
Explanation:
Firstly, cations refers to the positively charged atom in the ionic compound, which is Na+.
Given the mass of NaCl as 1.17g, the number of moles of NaCl can be calculated this:
Molar mass of NaCl = 23 + 35.5
= 58.5g/mol
Mole = mass/molar mass
Mole = 1.17/58.5
Mole = 0.02moles
Using Avagadro's number, 6.022 × 10^23 atoms of Na+ are in 1 mole of NaCl.
In 0.02 moles of NaCl, there are 0.02 × 6.022 × 10^23 of Na+
0.1204 × 10^23 atoms
1.2 × 10^22 atoms of Na+ (cation)