All categories

3 years ago

What is the density of object A? Does it sink or float in water?

Chemistry

1 answer:

Oksana_A [137]3 years ago

3 0

Answer:

~1.5 g/cm3 and it does NOT float in water.

Explanation:

If you look at the graph, Object A weighs ~6 grams and is ~4 cm3 in volume

Density = Mass/Volume

So 6 grams/4 cm3 = 1.5 g/cm3

Water has a density of 1 g/cm3 and because Object A density is higher than that of water, it sinks.

You might be interested in

For the reaction shown, calculate how many moles of NO2 form when each amount of reactant completely reacts.

Anton [14]

Answer:- 2.4 mol $NO_2$ .

Solution:- It asks to calculate the moles of $NO_2$ formed when 1.2 moles of $N_2O_5$ are reacted.

There is 2:4 mol ratio between $N_2O_5$ and $NO_2$ . So, the moles of reactant are multiplied by the mol ratio to get the moles of $NO_2$ . The calculations are shown below:

$1.2mol N_2O_5(\frac{4mol NO_2}{2mol N_2O_5})$

= 2.4 mol $NO_2$

So, 2.4 moles of $NO_2$ are formed when 1.2 moles of $N_2O_5$ were reacted.

7 0

3 years ago

Read 2 more answers

Why is oxygen written with a subscript 2 in CO2?

Alexeev081 [22]

Answer:

Explanation:

the answer is b

6 0

3 years ago

Read 2 more answers

Calculate the enthalpy of the reaction

harkovskaia [24]

Answer : The enthalpy of the reaction is, -2552 kJ/mole

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The given enthalpy of reaction is,

$4B(s)+3O_2(g)\rightarrow 2B_2O_3(s)$ $\Delta H=?$

The intermediate balanced chemical reactions are:

(1) $B_2O_3(s)+3H_2O(g)\rightarrow 3O_2(g)+B_2H_6(g)$ $\Delta H_A=+2035kJ$

(2) $2B(s)+3H_2(g)\rightarrow B_2H_6(g)$ $\Delta H_B=+36kJ$

(3) $H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l)$ $\Delta H_C=-285kJ$

(4) $H_2O(l)\rightarrow H_2O(g)$ $\Delta H_D=+44kJ$

Now we have to revere the reactions 1 and multiple by 2, revere the reactions 3, 4 and multiple by 2 and multiply the reaction 2 by 2 and then adding all the equations, we get :

(when we are reversing the reaction then the sign of the enthalpy change will be change.)

The expression for enthalpy of the reaction will be,

$\Delta H=-2\times \Delta H_A+2\times \Delta H_B-6\times \Delta H_C-6\times \Delta H_D$

$\Delta H=-2(+2035kJ)+2(+36kJ)-6(-285kJ)-6(+44)$

$\Delta H=-2552kJ$

Therefore, the enthalpy of the reaction is, -2552 kJ/mole

4 0

3 years ago

36. Dimensional Analysis: A useful way to convert units using multiplication & division *Always start with what you are give

ollegr [7]

Answer:

A) 7.9 x 10⁶ inches

B) 1004 g

C) 2.8 x 10³ inches/ min

D) 1.2 x 10⁻⁴ mm

Explanation:

A) Since 39.37 inches = 1 m, you can convert meters to inches by multiplying by the conversion factor (39.37 inches / 1 m).

Notice that if 39.37 inches = 1 m then 39.37 inches / 1 m = 1. That means that when you multiply by a conversion factor, you are only changing units since it is the same as multiplying by 1 :

2.0 x 10⁵ m * (39.37 inches / 1 m) = 7.9 x 10⁶ inches

B) Conversion factors : (2.205 pounds / 1 kg) and (453.59 g / 1 pound), because 2.205 pounds = 1 kg and 1 pound = 453.59 g. Then:

1.004 kg * ( 2.205 pounds / 1 kg) * ( 453.59 g / 1 pound) = 1004 g

C) Conversion factor: (39.37 inches / 1 m) and (60 s / 1 min)

1.2 m/s * (39.37 inches / 1 m) * ( 60 s / 1 min) = 2.8 x 10³ inches/ min

D)Converison factor ( 1 mm / 1 x 10⁶ nm):

120 nm (1 mm / 1 x 10⁶ nm) = 1.2 x 10⁻⁴ mm

3 0

3 years ago

Read 2 more answers

Which is NOT a property of gold?

DENIUS [597]

Answer:

Rareness, the others describe what the gold is and its properties.

6 0

3 years ago