he specific heat capacity of a pure substance can be found by dividing the heat needed to change the temperature of a sample of the substance by the mass of the sample and by the change in temperature. The heat capacity of a certain substance has been measured to be

Complete question is;

The specific heat capacity of a pure substance can be found by dividing the heat needed to change the temperature of a sample of the substance by the mass of the sample and by the change in temperature. The specific heat capacity of a certain substance has been measured to be 3.52 J/g°C. Suppose 420.0 g of the substance is heated until the temperature of the sample has changed by 43.8 °C.

Write an equation that will let you calculate the last Q that was needed for this temperature change. Your equation should contain only symbols. Be sure to define each symbol.

Q = m•c•Δt

Q = 64753.92 J

Explanation:

We are given;

Mass (m) = 420 g

Change in temperature; (Δt) = 43.8 °C

Specific heat capacity (c) = 3.52 J/g °C

The last Q is simply the heat energy that caused that temperature change.

This is given by the formula;

Q = m•c•Δt

Plugging in the relevant values;

Q = 420 × 3.52 × 43.8

Q = 64753.92 J

answer: option (a) is the correct answer.

explanation:

the measurement of hydrogen ions in a solution is known as ph.

if ph of a solution is less than 7 then the solution is acidic. if ph of a solution is greater than 7 then the solution is basic.

when the ph of a solution equals 7, then the solution is considered as neutral.

the ph of pure water is 7, therefore, it means that concentration of hydronium ions equals that of hydroxide ions.