D will because water just turns from liquid to a gas by adding heat. That is a physical change. The other equations are chemical changes.
Answer:
111.68 g
Explanation:
Given data:
Mass of HgS needed = ?
Mass of CaS produced = 26.0 g
Solution:
Chemical equation;
4HgS + 4CaO → 4Hg + 3CaS + CaSO₄
Number of moles of CaS:
Number of moles = mass/molar mass
Number of moles = 26 g/ 72.143 g/mol
Number of moles = 0.36 mol
Now we will compare the moles of HgS with CaS.
CaS : HgS
3 : 4
0.36 : 4/3×0.36 = 0.48 mol
Mass of HgS:
Mass = number of moles × molar mass
Mass = 0.48 mol × 232.66 g/mol
Mass = 111.68 g
<span>its because they're both structured the same way. for example the sun and the nucleus are the same (in the centre) and the electrons and planets orbiting are the same</span>
Answer:
The nucleus has an overall positive charge as it contains the protons. Every atom has no overall charge (neutral). This is because they contain equal numbers of positive protons and negative electrons. These opposite charges cancel each other out making the atom neutral.
Explanation:
Answer:
Activation energy for the uncatalyzed reverse reaction = 103 kJ/mol
Explanation:
Activation energy decreases from = 56 kj/mol to 35 kj/mol
products = 78 KJ lower in energy than reactants
Activation energy for the uncatalyzed reverse reaction = 103 kJ/mol
attached below are the sketches of approximate energy-level for both catalyzed and uncatalyzed reactions
