Answer:
The heat needed to warm 25.3 g of copper from 22°C to 39°C is 165.59 Joules.
Explanation:

Where:
Q = heat absorbed or heat lost
c = specific heat of substance
m = Mass of the substance
ΔT = change in temperature of the substance
We have mass of copper = m = 25.3 g
Specific heat of copper = c = 0.385 J/g°C
ΔT = 39°C - 22°C = 17°C
Heat absorbed by the copper :

The heat needed to warm 25.3 g of copper from 22°C to 39°C is 165.59 Joules.
Answer:
2Zn + 2HCI ➡️ ZnCI2 + H2
LHS of equation
Z = 2
H = 2
Cl = 2
RHS of equation
Zn = 1
Cl =2
H =2
as Zn is not equal in number of atoms on both sides of the equation, the equation does not obey the law of conservation of mass
Explanation:
the law of conservation mass states that the mass of an isolated system cannot be created nor destroyed by any chemical reaction or physical transformation. thus, there must be an equal number of atoms of an element present on both sides of the equation.
Answer:
There are 3, 64 moles of NaCl.
Explanation:
First we calculate the mass of 1 mol of NaCl, starting from the atomic weights of Na and Cl obtained from the periodic table. Then we calculate themoles in 213 grams of NaCl, making a simple rule of three:
Weight NaCl= Weight Na + Weight Cl = 23 g + 35, 5 g= 58, 5 g/ mol
58,5 g ------1 mol NaCl
213 g---------x= (213 g x 1 mol NaCl)/ 58, 5 g= <em>3, 64 mol NaCl</em>
! mole of CO2 at STP has a volume of 22.4 liters
88 grams = 2 moles
so the required volume = 2*22.4 = 44.8 liters
Answer:
373.1 mL of AgCN (aq) must be poured into your electrolysis vat to ensure you have sufficient Ag to plate all of the forks.
Explanation:
Mass of silver to be precipitated on ecah spoon = 0.500 g
Number of silver spoons = 250
Total mass of silver = 250 × 0.500 g = 125 g

Moles of AgCN = n = 
Volume of AgCN solution =V
Molarity of the AgCN = 2.50 M

(1 L = 1000 mL)
373.1 mL of AgCN (aq) must be poured into your electrolysis vat to ensure you have sufficient Ag to plate all of the forks.