4. Ellie uses 12.5 pounds of potatoes to make mashed potatoes. She uses one-tenth as many pounds of butter as potatoes. How many pounds of butter does Ellie use?

Answer:

The answer = 6

Step-by-step explanation:

Given expression:

To evaluate the  given expression, when and

Solution:

We have:

Plugging in and in the given expression, to evaluate.

⇒

Evaluating:

⇒

⇒ 6(Answer)

Answer:

hmm 6

Step-by-step explanation:

Answer:

The enthalpy change per mole of sodium when sodium reacts with water is 28.36 kJ

Step-by-step explanation:

The given parameters are;

Mass of sodium = 8 grams = 0.008 kg

Volume of water = 227 cm³ = 0.000227 m³

Initial water temperature, T₁ = 298 K

Final water temperature, T₂ = 308.4 K

Specific heat capacity of water = 4.18 J/(K·g)

Density of water = 1000 kg/m³

Mass of water = 1000×0.000227 = 0.227 kg = 227 g

Heat change, ΔH = m×c×ΔT = m×c×(T₂ - T₁)

ΔH = 227*4.18*(308.4 - 298) = 9868.144 J = 9.868 kJ

Molar mass of sodium = 22.989769 g/mol

Therefore, 8 grams contains;

8/22.989769 = 0.348 moles of Na

Which gives the enthalpy change per 0.348 moles of Na when sodium reacts with water = 9.868 kJ

Therefore, when one mole of Na reacts with water we have;

The enthalpy change per 0.348/0.348 = 1 mole of Na when sodium reacts with water = 9.868 kJ/0.348 = 28,358.3 J = 28.36 kJ.

Answer:

Peggy completed more of the math homework than Al

Step-by-step explanation:

we have

Peggy completed of the math homework

Al completed of the math homework

we know that

In order to be able to compare fractions more easily it is recommended that both have the same denominator

so

Multiply by

Multiply by

therefore

Peggy completed more of the math homework than Al