i am there but i can't talk now
cause my mom is calling
but sorry!!
<span>Answer:
Mass % KCL:
Add the grams of both compounds (31.0 g KCL + 225 g water) to find total mass and then divide the grams of KCL over the total mass, then multiply by 100: ( 31.0 g KCL / 31.0 g + 225 G) * 100%
Mole fraction KCL
Calculate the moles of KCL and water and add them to find the total moles (Moles of KCL + moles of water). Then, divide the number of KCL moles over the total moles.
moles of KCL/ moles kcl + moles water= mole fraction of KCL</span>
The reaction represents the law of conservation of mass (a balanced chemical equation :
2NaN₃ → 2Na + 3N₂
<h3>Further explanation
</h3>
Conservation of mass applies to a closed system, where the masses before and after the reaction are the same, so balanced chemical equations show that mass is conserved in chemical reactions.
So we just have to look at the amount of each type of element present in the reactants and products must be the same
1. Hg + O₂ → HgO
not balanced, because element O not equal(2 in left, 1 in right)
2. 2NaN₃ → 2Na + 3N₂
balanced, because element in reactant and product are the same
Na, left = 2, right=2
N, left =2x3=6, right=3x2=6
3. C+O → CO₂
not balanced, because element O not equal(1 in left, 2 in right)
4. CH₄ + O₂ → CO₂ +H₂O
not balanced, because element O and H not equal
+25 kJ; not spontaneous is your answer :) Hope this helps.