The Lewis dot diagram for LiBr

Which of the following is a physical change?

Wewaii [24]

Answer:

O ice melts at 0°C that is the answer

5 0

3 years ago

Low frequency waves have longer wavelength true or false

kap26 [50]

Answer:

True

Explanation:

Since the waves have low frequency that means the wavelength is going to be longer. Hope this helps

5 0

2 years ago

How many molecules of Mg3N2 (magnesium nitride) are formed when excess Mg (magnesium)

dybincka [34]

Explanation:

3Mg(s) + N2(g) = Mg3N2(s)

First check that the equation is balanced. In this case, it is.

Assuming that magnesium is the limiting reactant:

First find the molecular weight using the Periodic Table.

We find that the atomic mass of magnesium is approximately

24.3g, so the molecular weight is just 24.3g\mol

2. Next we need the mole to mole ratio. As there are 3

magnesiums for 1 magnesium nitride (shown by the coefficients), the

mole to mole ratio is 1 mol Mg3N2\3 mol Mg.

3. We need the amount of the substance, in grams. Since you have not

stated it in the question, I'll just do 10g AS AN EXAMPLE. Note that

depending on the amount, the LIMITING REAGENT MAY DIFFER.

4. Finally, we need the molecular weight of Mg3N2, which we can easily

calculate to be around 100.9\mol.

5. Putting this all together, we have 10gMg⋅ (mol Mg\24.3gMg)

(1mol Mg3N2\ 3mol Mg) (100.9g Mg3N2\mol Mg3N2)

the units will cancel to leave gMg3N2 (grams of magnesium nitride):

10gMg ⋅ (mol Mg\24.3gMg) (1mol Mg3N2\3mol Mg)

(100.9g Mg3N2\mol Mg3N2)

Doing the calculation yields approximately 13.84g.

Assuming that nitrogen is the limiting reactant:

Similarly, following the above steps but with 10g of nitrogen yields 36.04g

In conclusion, as we produce less amount of Mg3N2 when we assumed that Mg was the limiting reagent, magnesium is the limiting reagent and nitrogen is the excess.

Note: This is in THIS CASE, where we have 10g of both. The answer may vary depending on the amount of each substance.

7 0

2 years ago

Read 2 more answers

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

A typical lead acid storage battery like the one found in your car is 12 V and is rated at 70 amp-hr (70 amp of current drawn fo

xeze [42]

Answer:

Almost 3 snicker's bar will contain the worth of energy stored in the battery which makes option A correct (Fewer than 5)

Explanation:

Step 1

The energy stored in a charged battery is 840 Watt- hours

Recall from the question that 1 KWh = 3600 KJ

So how many Kilo-joules will be in 840 Watt- hours?

I will convert 840 Watt- hours to KWh = 840 / 1000

= 0.840 KWh

Since I KWh gives 3600 KJ

then, 0.840 KWh will give x

x = 3024 KJ

3024 KJ of energy is stored in the battery

Step 2

A snicker bar contains 250 cal and 1 cal = 4.184 KJ

Convert 250 cal to KJ?

250 cal = 1046 KJ

Each snicker bar contains 1046 KJ

To calculate how many snicker's bar worth energy stored in the battery will be (y) ?

y = 3024 / 1046

y = 2.9 snicker's bar approximately 3

The correct option is Fewer than 5

3 0

2 years ago