The ratio of x to y is 4 to 12. Fill in numbers to form a table with the given ratio,

What is the average atomic mass of the element?

morpeh [17]

The average atomic mass of element X is 14.007 u.

The average atomic mass of X is the weighted average of the atomic masses of its isotopes.

We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its % abundance).

Thus,

0.996 36 × 14.003 u =13.952 03 u

0.003 64 × 15.000 u = 0.054 60 u

__________TOTAL = 14.007 u

7 0

3 years ago

"46.7 g of water at 80.6 oC is added to a calorimeter that contains 45.33 g of water at 40.6 oC. If the final temperature of the

soldier1979 [14.2K]

Answer: The specific heat of calorimeter is 30.68 J/g°C

Explanation:

When hot water is added to the calorimeter, the amount of heat released by the hot water will be equal to the amount of heat absorbed by cold water and calorimeter.

$Heat_{\text{absorbed}}=Heat_{\text{released}}$

The equation used to calculate heat released or absorbed follows:

$Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})$

$m_1\times c_1\times (T_{final}-T_1)=-[(m_2\times c_2)+c_3](T_{final}-T_2)$ ......(1)

where,

q = heat absorbed or released

$m_1$ = mass of hot water = 46.7 g

$m_2$ = mass of cold water = 45.33 g

$T_{final}$ = final temperature = 59.4°C

$T_1$ = initial temperature of hot water = 80.6°C

$T_2$ = initial temperature of cold water = 40.6°C

$c_1$ = specific heat of hot water = 4.184 J/g°C

$c_2$ = specific heat of cold water = 4.184 J/g°C

$c_3$ = specific heat of calorimeter = ? J/g°C

Putting values in equation 1, we get:

$46.7\times 4.184\times (59.4-80.6)=-[(45.33\times 4.184)+c_3](59.4-40.6)$

$c_3=30.68J/g^oC$

Hence, the specific heat of calorimeter is 30.68 J/g°C

6 0

3 years ago

A reaction is followed and found to have a rate constant of 3.36 × 104 m-1s-1 at 344 k and a rate constant of 7.69 m-1s-1 at 219

g100num [7]

The relation between rate constants at different temperatures, temperature and activation energy is known as Arrhenius equation

Arrhenius equation

$K=Ae^-{\frac{Ea}{RT} }$

For two temperatures

$Ea=R(\frac{ln\frac{k1}{k1} }{(\frac{1}{T1})-(\frac{1}{T2})})$

Where

Ea = ? = activation energy

k1 = 3.36 × 10⁴

T1=344 k

k2=7.69

T2=219K

R= gas constant = 8.314 J /molK

Putting values

$Ea= (8.314)(\frac{ln(\frac{7.69}{33600})}{(\frac{1}{344})(\frac{1}{219})}$

Ea = (-69.69)/(-0.00166) = 41981.93 J/mol

Or

Activation energy is 42.0 kJ /mol

3 0

3 years ago

The cells of a tomato contain mostly an aqueous solution of sugar and other substances. If a typical tomato freezes at -2.5 °C,

DIA [1.3K]

Answer:

1.35 m

Explanation:

We can solve this problem by using the freezing point depression formula:

ΔT = Kf * m * i

Where:

ΔT is the temperature difference between the freezing point of the pure solvent (water) and the solution. In this case it is (0 °C - -2.5 °C = 2.5 °C).

Kf is the cryoscopic constant, for water it is 1.853 °C*kg/mol.

m is the molality.

i is the van't Hoff factor, as sugar does not dissociate in water, it has a value of 1.

We input the data:

2.5 °C = 1.853 °C*kg/mol * m * 1

And solve for m:

m = 1.35 m

6 0

3 years ago

Ionic, covalent and metallic. How many of these can form giant structures?

Elena L [17]

Answer:

covalent

Explanation:

7 0

2 years ago

The ratio of x to y is 4 to 12. Fill in numbers toform a table with the given ratio,​

The ratio of x to y is 4 to 12. Fill in numbers toform a table with the given ratio,