Can you answer pls?
translation of the question: one mol of a metal, which has a density of 7,86 g/cm^3, occupies a volume of 7,10cm^3. of which metal are we speaking about?

Iron

Explanation:

Given data:

Density of metal = 7.86 g/cm³

Volume = 7.10 cm³

Moles of metal = 1 mol

Metal present = ?

Solution:

D = m/v

m = d×v

m =  7.86 g/cm³ × 7.10 cm³

m = 55.806 g

Number of moles = mass/ molar mass

Molar mass = mass/ number of moles

Molar mass =  55.806 g / 1 mol

Molar mass =  55.806 g/mol

The molar mass of iron is 55.8 so given data is about iron metal.

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

sorry i was late, but i don't know what assignment your talking about, i'm in flvs as well, im in earth space science. but u are behind pace bc every class should be in the 3's or 4'