Please help me! I don't understand this at all. All the info is in the picture. Thank you so much!!!

H₂S + Cl₂ —> S + 2HCl

Explanation:

? + Cl₂ —> S + 2HCl

To balance the equation above, we must recognise what atoms are present in the products.

The products contains S, H and Cl.

Thus, S, H and Cl must also be present in the reactants.

Considering the equation given above, we can see clearly that H and S is missing in the reactants.

H and S together as a compound is expressed as H₂S.

Now, we shall input H₂S into the equation to obtain the complete equation. This is illustrated below:

? + Cl₂ —> S + 2HCl

H₂S + Cl₂ —> S + 2HCl

Next, we shall verify to see if the equation is balanced.

There are 2 atoms of H on both sides of the equation.

There are 2 atoms of Cl on both sides of the equation.

1 atom of S exist on both sides of the equation.

Thus, the equation is balanced.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol