Cr
Hope that helps, Good luck! (:
#1 is 6
#2 During chemistry lab, Mrs. Black’s students placed an antacid tablet in a zip lock bag. They recorded the mass of the tablet in the bag. Then they carefully added 50 grams of water and quickly sealed the bag. The tablet began to fizz and soon disappeared. The bag was filled with gas and it felt cold to the touch.
16 grams.
Looking at the reaction equation, it's evident that for each mole of HBr
consumed, 1 mole of CO2 will be produced. So let's calculate the molar mass
of HBr and CO2 first.
Atomic weight hydrogen = 1.00794
Atomic weight bromine = 79.904
Atomic weight carbon = 12.0107
Atomic weight oxygen = 15.999
Molar mass HBr = 1.00794 + 79.904 = 80.91194 g/mol
Molar mass CO2 = 12.0107 + 2*15.999 = 44.0087 g/mol
Moles HBr = 30 g / 80.91194 g/mol = 0.370773461 mol
Grams CO2 = 0.370773461 mol * 44.0087 g/mol = 16.317258 g
Rounding to 2 significant digits gives 16 grams.
Answer:
The Cl⁻ and K⁺ are spectator ions.
Explanation:
Balanced Chemical equation:
BaCl₂(aq) + K₂CrO₄(aq) → BaCrO₄(s) + 2KCl (aq)
Ionic equation:
Ba²⁺(aq) + 2Cl⁻(aq) + 2K⁺(aq) + CrO₄²⁻(aq) → BaCrO₄(s) + 2k⁺(aq) + 2Cl⁻ (aq)
Net ionic equation:
Ba²⁺(aq) + CrO₄²⁻(aq) → BaCrO₄(s)
The Cl⁻ and K⁺ are spectator ions that's why these are not written in net ionic equation. The BaCrO₄ can not be splitted into ions because it is present in solid form.
Spectator ions:
These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.
2moles
1.20moles
0.5mole
Explanation:
Given parameters:
Mass of He = 8g
Mass of Zn = 78g 
Volume of oxygen gas= 11.2L
Unknown:
Number of moles of He, Zn = ?
Number of moles of oxygen gas = ?
Solution;
Number of moles of substances is given as :
Number of moles = 
molar mass of He = 4g/mol
molar mass of Zn = 65.4g/mol
Number of moles of He = 
= 2moles
Number of moles of Zn = 
1.20moles
For gases at STP;
Number of moles = 
Number of moles = 
= 0.5mole
learn more:
Number of moles brainly.com/question/1841136
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