Mass/ energy can not be created or destroyed
Answer:
4.25% is the final concentration of phosphoric acid.
Explanation:
Initial concentration of phosphoric acid = 
Initial volume of phosphoric acid = 
Final concentration of phosphoric acid = 
Final volume of phosphoric acid = 
( 1L = 1000 mL)
4.25% is the final concentration of phosphoric acid.
Answer:
84.11 g/mol
Explanation:
A metal from group 2A will form the cation M²⁺, and the ion carbonate is CO₃²⁻, so the metal carbonate must be: MCO₃, and the reaction:
MCO₃(s) → MO(s) + CO₂(g)
For the stoichiometry of the reaction, 1 mol of MCO₃(s) will produce 1 mol of CO₂. Using the ideal gas law, it's possible to calculate the number of moles of CO₂:
PV = nRT , where P is the pressure, V is the volume(0.285 L), R is the gas constant (62.36 mmHg*L/mol*K), n is the number of moles, and T is the temperature (25 + 273 = 298 K).
69.8*0.285 = n*62.36*298
18583.28n = 19.893
n = 0.00107 mol
So, the number of moles of the metal carbonate is 0.00107. The molar mass is the mass divided by the number of moles:
0.0900/0.00107 = 84.11 g/mol
Answer:
Let, X be the oxidation state of Cr in K
2
Cr
2
O
7
.
2(+1)+2X+7(−2)=0
2+2X−14=0
2X=12
X=+6
Hence, the oxidation state of Cr in K
2
Cr
2
O
7
is +6.
Mechanical energy of the firefighter moving
