All categories

3 years ago

Which metal is more active than H2? (1) Ag (3) Cu (2) Au (4) Pb

Chemistry

1 answer:

astraxan [27]3 years ago

5 0

Answer is (4) - Pb.

According to the reactivity series of elements

- the elements which are above the hydrogen are more reactive than hydrogen.

- the elements which are below the hydrogen are less reactive than hydrogen.

Among the given choices, only Pb is placed above the hydrogen in the reactivity series and rest are below the hydrogen.

Hence, Pb is more active than hydrogen.

You might be interested in

If a car passes a pedestrian, a change in pitch is __________.

enot [183]

Given two questions:

1) If a car passes a pedestrian, a change in pitch is ______________.
The answer is the change in pitch is perceived by the pedestrian since he is the one in a relatively constant position compared to the car passing.

2) In the Doppler Effect lab, which statement best describes what you demonstrated about speed and pitch?

The answer is 'speed and direction affect pitch'.

6 0

3 years ago

Read 2 more answers

Calculate the molality of 75.0 grams of MgCl2 (molar mass=95.21 g/mol) dissolved in 500.0 g of solvent.

nordsb [41]

Answer: The molality of magnesium chloride is 1.58 m

Explanation:

To calculate the molality of solution, we use the equation:

$\text{Molality}=\frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

Where,

$m_{solute}$ = Given mass of solute (magnesium chloride) = 75.0

$M_{solute}$ = Molar mass of solute (magnesium chloride) = 95.21 g/mol

$W_{solvent}$ = Mass of solvent = 500.0 g

Putting values in above equation, we get:

$\text{Molality of }MgCl_2=\frac{75.0\times 1000}{95.21\times 500.0}\\\\\text{Molality of }MgCl_2=1.58m$

Hence, the molality of magnesium chloride is 1.58 m

5 0

4 years ago

Read 2 more answers

A potassium bromide solution is 8.30% potassium bromide by mass and its density is 1.03 g/ml. what mass of potassium bromide is

pshichka [43]

Answer: The mass of potassium bromide present in 41.2 mL of solution will be 3.522 grams.

Explanation:

We are given that KBr is present in 8.3% KBr solution, which means that 8.3 grams of potassium bromide is present in 100 gram of the solution.

To calculate the volume of KBr, we use the formula:

$Density=\frac{Mass}{Volume}$

Mass of the solution = 100 grams

Density of KBr solution = 1.03g/mL

Volume of the solution = ? mL

Putting values in above equation, we get:

$1.03g/mL=\frac{100g}{Volume}\\\\Volume=97.08mL$

Now, to calculate the mass of KBr in 41.2mL of the solution, we use unitary method.

In 97.08 mL of solution, mass of KBr present is 8.3 grams.

So, 41.2 mL of solution will contain = $\frac{8.3g}{97.08mL}\times 41.2mL=3.522g$ of KBr.

Hence, the mass of potassium bromide present in 41.2 mL of solution will be 3.522 grams.

7 0

3 years ago

In cellular respiration glucose is oxidized to three compounds

7nadin3 [17]

CO2 + H2O + Energy are the comments

7 0

3 years ago

Two samples of a compound containing elements a and b are decomposed. the first sample produces 15 g of a and 35 g of

Alborosie

According to law of definite proportion, for a compound, elements always combine in fixed ratio by mass.

The formula of compound remains the same, let it be a_{x}b_{y} where, a and b are two different elements.

Since, the ratio of mass remains the same , calculate the ratio of masses of element a and b in both cases

\frac{a}{b}=\frac{15}{35}=\frac{10}{y}

rearranging,

y=\frac{10\times 35}{15}=23.3

Thus, mass of b produced will be 23.3 g.

3 0

3 years ago