All categories

3 years ago

If 5 milliliters of a liquid has a mass of 10 grams what is the density of the liquid

1 answer:

4 0

So density = mass ÷ volume

∴ if mass of liquid = 10 g and volume = 5 ml

then density of liquid = 10 g ÷ 5 ml

= 2 g / ml

You might be interested in

6. The nuclear reaction where Si-30 becomes P-30 is

Arisa [49]

Answer:c

Explanation:

8 0

3 years ago

A 0.595 g sample of a metal, M, reacts completely with sulfuric acid according to the reaction M ( s ) + H 2 SO 4 ( aq ) ⟶ MSO 4

zalisa [80]

Answer:

molar mass M(s) = 65.326 g/mol

Explanation:

M(s) + H2SO4(aq) → MSO4(aq) + H2(g)

∴ VH2(g) = 231 mL = 0.231 L

∴ P atm = 1.0079 bar

∴ PvH2O(25°C) = 0.03167 bar

Graham´s law:

⇒ PH2(g) = P atm - PvH2O(25°C)

⇒ PH2(g) = 1.0079 bar - 0.03167 bar = 0.97623 bar = 0.9635 atm

∴ nH2(g) = PV/RT

⇒ nH2(g) = ((0.9635 atm)(0.231 L))/((0.082 atmL/Kmol)(298 K))

⇒ nH2(g) = 9.1082 E-3 mol

⇒ n M(s) = ( 9.1082 E-3 mol H2(g) )(mol M(s)/mol H2(g))

⇒ n M(s) = 9.1082 E-3 mol

∴ molar mass M(s) [=] g/mol

⇒ molar mass M(s) = (0.595 g) / (9.1082 E-3 mol)

⇒ molar mass M(s) = 65.326 g/mol

7 0

3 years ago

Calculate the number of hydrogen atoms present in 40g of urea, (NH2)2CO

tekilochka [14]

Answer: There are $16.14 \times 10^{23}$ atoms of hydrogen are present in 40g of urea, $(NH_{2})_{2}CO$ .

Explanation:

Given: Mass of urea = 40 g

Number of moles is the mass of substance divided by its molar mass.

First, moles of urea (molar mass = 60 g/mol) are calculated as follows.

$Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol$

According to the mole concept, 1 mole of every substance contains $6.022 \times 10^{23}$ atoms.

So, the number of atoms present in 0.67 moles are as follows.

$0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms$

In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.

$4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms$

Thus, we can conclude that there are $16.14 \times 10^{23}$ atoms of hydrogen are present in 40g of urea, $(NH_{2})_{2}CO$ .

7 0

2 years ago

How would you describe the following chemical reaction?

GREYUIT [131]

Answer:

Explanation:

The normal way to express an energy reaction is to put the energy on the left. Then you can make a rule.

If the energy on the left is plus then the reactants require energy. The reaction is endothermic -- energy is taken from the environment.
If the energy is minus when it is on the left. then the reactants give up energy. The reaction is exothermic and energy is given to the environment.

2CO(g)+O2(g) - energy --> 2CO2(g)

Exothermic

4 0

2 years ago

What is the molecular formula for a compound that is 44.87% potassium, 36.7%

Phoenix [80]

Answer:

Molecular formula: S4K8O16 empirical formula: SK2O4

Explanation:

First we find the moles of each by first finding grams (using the percent) and then using stoichiometry to convert into moles:

Sulfur: 696 *.18 = 125.28grams S* $\frac{1 mole S}{32.065 g S} = 3.907 moles S$

Potassium: 696 *.4487 = 312.2952 * $\frac{1 mole K}{39.08 g K}$ = 7.99117 mole K

Oxygen: 696 * .367 = 255.432 * $\frac{1 mol O}{16g O}$ = 15.9654 mole O

Then we divide each value by the atom with the smallest number of moles to find the mole ratio:

3.907/3.907= 1

7.99117 mole K/ 3.907= 2.043

15.9654 mole O/ 3.907= 4.08

The empirical formula is SK2O4

To find the molecular formula, we divide the mass given (696) by the mass of the empirical formula (174.22) to get 4. We then divide each atom by 4.

Molecular formula: S4K8O16

5 0

3 years ago