How many significant figures are in 0.00120

kobusy [5.1K]

Its to protect the cell from its surroundings, its selectively permeable to ions and organic molecules

7 0

2 years ago

El plomo y el yodo forman dos compuestos. En uno, el porcentaje de en masa de plomo es del 44,94% y en el otro es de 62,02%. Cal

nikdorinn [45]

Answer:

0.8162 gramos de plomo por gramo de yodo

1.633 gramos de plomo por gramo de yodo

Explanation:

Asumiendo una base de 100 gramos para cada compuesto:

Primer compuesto:

Gramos plomo: 44.94g

Gramos de yodo: 100-44.94g = 55.06g

Así, la masa de plomo por gramos de yodo para el primer compuesto es:

44.94g plomo / 55.06g Yodo =

0.8162 gramos de plomo por gramo de yodo

Segundo compuesto:

Gramos plomo: 62.02g

Gramos de yodo: 100-62.02g = 37.98g

La masa de plomo por gramos de yodo para el segundo compuesto es:

62.02g plomo / 37.98g Yodo =

1.633 gramos de plomo por gramo de yodo

8 0

2 years ago

High concentrations of ammonia (NH3), nitrite ion, and nitrate ion in water can kill fish. Lethal concentrations of these specie

kykrilka [37]

Explanation:

It is known that molality is the number of moles present in kg of solution.

Mathematically, Molality = $\frac{\text{no. of moles of solute}}{\text{mass of solvent in Kg}}$

The given data is as follows.

Molar mass of ammonia = 17 g/mol

Concentration = 1.002 mg/L = $\frac{0.001002 g/L}{17 g/mol}$

= $5.89 \times 10^{-4}$ mol/L

Also, density = $\frac{1 g}{mL}$ = 1 kg/L

Therefore, molality will be calculated as follows.

Molality = $\frac{5.89 \times 10^{-4} mol/L}{1 kg/L}$

= $5.89 \times 10^{-4} mol/kg$

And,

Molar mass of nitrite = 46 g/mol

Concentration = 0.387 mg/L = $\frac{0.000412 g/L}{46 g/mol}$

= $8.956 \times 10^{-6}$ mol/L

And, density = $\frac{1 g}{mL}$ = 1 kg/L

Hence, molality = $\frac{8.956 \times 10^{-6} mol/L}{1 kg/L}$

= $8.956 \times 10^{-6}$ mol/kg

Now, Molar mass of nitarte = 62 g/mol

Concentration = 1352.2 mg/L

= $\frac{1.3522 g/L}{62 g/mol}$

= 0.02181 mol/L

Also, density = $\frac{1 g}{mL}$ = 1 kg/L

Hence, molality will be calculated as follows.

Molality = $\frac{0.02181 mol/L}{1 kg/L}$

= 0.02181 mol/kg

Therefore, molality of given species is $5.89 \times 10^{-4} mol/kg$ for ammonia, $8.956 \times 10^{-6}$ mol/kg for nitrite, and 0.02181 mol/kg for nitrate ion.

7 0

3 years ago

A number of substances and their chemical formulas are listed below. Check the ones that are compounds. neon (Ne) carbon monoxid

Oxana [17]

Answer:

carbon monoxide (CO)

glucose (C6H12O6)

Explanation:

4 0

3 years ago

Three blocks of metal at the same temperature are placed on a hot stove. Their specific heat capacities are listed below.Rank th

JulijaS [17]

Answer:

Copper>Steel>Aluminium

Explanation:

Hello,

Since the heat capacity accounts for the required heat to increase by 1°C, 1 kg of the metal, copper is the one that has the lower heat capacity, it means that it requires the least amount of energy to warm up (increase its temperature), this could be substantiated via the mathematical definition of heat capacity:

$H=mC(T_2-T_1)$

Solving for $T_2$ :

$T_2=T_1+\frac{H}{mC}$

It means that the lower the heat capacity, the higher the final temperature.

Best regards.

7 0

3 years ago