Question

Каждое утро юный химик Иван готовит своей маленькой сестре чай. Однажды он задумался: "Чему равна массовая доля сахара в чае, если я кладу на стакан 3 чайные ложки сахара с горкой?. Помогите Ивану ответить на его вопрос, зная, что в 1 чайной ложку содержится сахара с горкой 7г., V(H2O)=250мл. m(раствора чая без сахара) =m(H2O)

Answer 1

Масса сахара = 3*7 = 21 г.
Масса чая = 250 г.
Масса раствора = 250+21 = 271 г
ω(сахара) = 21/271*100 = 7,75%

Answer 2

Calculation of the Mass Fraction of Sugar in Tea

To calculate the mass fraction of sugar in tea, we need to know the mass of the sugar added and the total mass of the tea solution.

Given: - Ivan adds 3 heaping teaspoons of sugar to a glass of tea. - Each heaping teaspoon contains 7 grams of sugar. - The volume of the tea solution (V(H2O)) is 250 ml.

To find the mass fraction of sugar in the tea, we can use the following formula:

Mass Fraction of Sugar = (Mass of Sugar) / (Mass of Tea Solution)

Let's calculate the mass fraction of sugar in the tea.

1. Calculate the mass of the sugar added: - Ivan adds 3 heaping teaspoons of sugar. - Each heaping teaspoon contains 7 grams of sugar. - Therefore, the mass of the sugar added is 3 * 7 = 21 grams. 2. Calculate the mass of the tea solution: - The volume of the tea solution is given as 250 ml. - However, we need to convert the volume from milliliters to grams, assuming the density of water. - The density of water is approximately 1 gram/ml. - Therefore, the mass of the tea solution is 250 grams. 3. Calculate the mass fraction of sugar in the tea: - Mass of Sugar = 21 grams - Mass of Tea Solution = 250 grams - Mass Fraction of Sugar = (21 grams) / (250 grams) = 0.084 or 8.4% (rounded to one decimal place)

Therefore, the mass fraction of sugar in the tea is approximately 8.4%.

Please note that the calculation assumes that the sugar dissolves completely in the tea and that there are no other solutes present in the tea solution.