Which statement is true for a solution when its concentration of hydroxide ions increases?

Calculate the specific heat of a piece of wood if 2000 g of wood absorbs 75,250 J of heat, and its temperature changes from 30°C

inna [77]

Answer:

C

Explanation:

The specific heat capacity=quantity of heat in joule/mass×change in temperature

from this question the quantity of heat is 75250,the mass is 2000 and the change in temperature is 50-30

which is 20

therefore

c=75250/2000×20

c=75250/40000

c=1.88

I hope this helps

3 0

3 years ago

Deep sea divers use a mixture of helium and oxygen to breathe. Assume that a diver is going to a depth of 150 feet where the tot

Svetlanka [38]

Answer:

4.525% is the percentage by volume of oxygen in the gas mixture.

Explanation:

Total pressure of the mixture = p = 4.42 atm

Partial pressure of the oxygen = $p_1=0.20 atm$

Partial pressure of the helium = $p_2$

$p_1=p\times \chi_1$ (Dalton law of partial pressure)

$0.20 atm=4.42 atm\times \chi_1$

$\chi_1=\frac{0.20 atm}{4.42 atm}=0.04525$

$\chi_2=1-\chi_1=1-0.04525=0.95475$

$chi_1+chi_2=1$

$n_1=0.04525 mol,n_2=0.95475 mol$

According Avogadro law:

$Moles\propto Volume$ (At temperature and pressure)

Volume occupied by oxygen gas = $V_1$

Total moles of gases = n = 1 mol

Total Volume of the gases = V

$\frac{n_1}{V_1}=\frac{n}{V}$

$\frac{V_1}{V}=\frac{n_1}{n}=\frac{0.04525 mol}{1 mol}$

Percent by volume of oxygen in the gas mixture:

$\frac{V_1}{V}\times 100=\frac{0.04525 mol}{1 mol}\times 100=4.525\%$

6 0

3 years ago

1, 2 and 3 ........

Orlov [11]

2.) Average atomic mass =Σ (abundance x molar mass) /100 = (12.64 x 302.04 + 18.23 x 304.12 + 69.13 x 305.03) /100 =304.486 u(Dalton) . This is avg atomic mass.

8 0

3 years ago

3. How many moles are 1.707 x 10^24 atoms of carbon?

Paraphin [41]

Answer:

2.835 moles of carbon

Explanation:

By definition, there are 6.022x10^23 atoms (or compounds) in one mole.

Write and use this as a conversion factor:

(6.022x10^23 atoms)/mole

(1.707 x 10^24 atoms of carbon)/((6.022x10^23 atoms)/mole) = 2.835 moles carbon

8 0

2 years ago

what is the balanced equation for the reaction of solid magnesium metal with oxygen gas to produce solid magnesium oxide

GaryK [48]

Answer:

2Mg + O₂ ⟶ 2MgO

Explanation:

Step 1. Start with the most complicated-looking formula (O₂?).

Put a 1 in front of it.

Mg + 1O₂ ⟶ MgO

Step 2. Balance O.

We have fixed 2 O on the left. We need 2O on the right. Put a 2 in front of MgO.

Mg + 1O₂ ⟶ 2MgO

Step 3. Balance Mg.

We have fixed 2 Mg on the right-hand side. We need 2 Mg atoms on the left. Put a 2 in front of Mg.

2Mg + 1O₂ ⟶ 2MgO

Every formula now has a coefficient. The equation should be balanced. Let’s check.

Atom On the left On the right

Mg 2 2

O 2 2

All atoms are balanced.

The balanced equation is

2Mg + O₂ ⟶ 2MgO

4 0

3 years ago