An experimenter places a piece of solid metal weighing 255g into a graduated cylinder which she then fills with mercury. After w

Answer:

Explanation:

Assuming all calculations occur at standard pressure and a temperature of -1.72°C :

Where

is the number of moles of hydrogen

is the mass of hydrogen

is the density of hydrogen

Answer: Pentane C5H12

Explanation:

The boiling point is defined as the temperature at which a liquid's vapor pressure matches the external pressure, causing the liquid to turn into vapor.

This compound is likely Pentane, represented as C5H12, since its boiling point falls between that of Butane, with the formula C4H10, and Hexane, with the formula C6H14.

Answer:

B, D

Explanation:

We need to recognize that the ice will rise in temperature from -6.5 ºC to 0 ºC for it to change into water.

Let's define q₁ as the heat needed to warm the ice to 0ºC, and q₂ as the heat for the transition from solid to liquid.

The calculation for q₁ is as follows:

q₁ = s x m x ΔT, where s represents the specific heat of ice (2.09 J/gºC), m is the mass, and ΔT is the temperature difference.

For q₂, the enthalpy of fusion is computed as:

q₂ = C x ΔT

with C indicating the specific heat for the phase transition, denoted as AH in kJ/mol.

All necessary data for computing q₁, q₂, and the total heat change (q₁ + q₂) is provided.

q₁ = 25.0 g x (2.09 J/gºC) x (0 - (-6.5 ºC))

q₁ = 339.6 J = 0.339 kJ

q₂ = (25 g/18 g/mol) x 6.02 kJ/mol = 1.39 x 6.02 kJ = 8.36 kJ

Combining these values gives us qtotal = 0.339 kJ + 8.36 kJ = 8.70 kJ.

Now we can answer the question:

(a) False, AH refers to the heat capacity during melting.

(b) True, as we concluded earlier.

(c) False, there’s only one phase transition from solid (ice) to liquid.

(d) True based on our calculations above.

(e) False, according to our findings.

After four hours of cooling, the soup reached a temperature of 140 F (or) 42 C.

Explanation:

A food worker allowed a cup of soup to cool for two hours,

step 1: The temperature attained in two hours is 70 F (or) 21 C

step 2: Consequently, in four hours, this doubles the value

Therefore, the temperature after four hours is 2(70)= 140 F (or) 2(21)= 42 C

Given:

Some statements.

To Find:

Identifying the SI units for each case.

Solution:

1) The unit is seconds, represented as seconds.

2) The unit of mass is kilograms (kg). (Note: pounds are not used because the S.I unit is kg)

3) In discussing length, the unit is the meter.

4) The SI unit for volume is meter³.