Metals can be found____ the “staircase”in the periodic table.

two substances react and the mass is recorded.The mass of the products does not equal the mass of the reactants .Which is the be

Dovator [93]

Mass can’t be destroyed. So since not all the mass was found in the products, that simply means that it was lost to the environment. For example, let’s say hydrogen and oxygen are the reactants and we get water in the product. Now that oxygen could have reacted with something else that we didn’t take into account when measuring the mass of the H2O released.

Tldr, some of the reactants were lost to the surroundings

8 0

3 years ago

Gold is alloyed (mixed) with other metals to increase its hardness in making jewelry.

KiRa [710]

Answer:

A) 54.04%

B) 13-karat

Explanation:

A) From the problem we have

1) Mg + Ms = 9.40 g

2) Vg + Vs = 0.675 cm³

Where M stands for mass, V stands for volume, and g and s stand for gold and silver respectively.

We can rewrite the first equation using the density values:

3) Vg * 19.3 g/cm³ + Vs * 10.5 g/cm³ = 9.40

So now we have a system of two equations (2 and 3) with two unknowns:

We express Vg in terms of Vs:

Vg + Vs = 0.675 cm³

Vg = 0.675 - Vs

We replace the value of Vg in equation 3:

Vg * 19.3 + Vs * 10.5 = 9.40

(0.675-Vs) * 19.3 + Vs * 10.5 = 9.40

13.0275 - 19.3Vs + 10.5Vs = 9.40

-8.8 Vs + 13.0275 = 9.40

Vs = 0.412 cm³

Now we calculate Vg:

Vg + Vs = 0.675 cm³

Vg + 0.412 cm³ = 0.675 cm³

Vg = 0.263 cm³

We calculate Mg from Vg:

0.263 cm³ * 19.3 g/cm³ = 5.08 g

We calculate the mass percentage of gold:

5.08 / 9.40 * 100% = 54.04%

B)

We multiply 24 by the percentage fraction:

24 * 54.04/100 = 12.97-karat ≅ 13-karat

4 0

3 years ago

What is the frequency of a wave traveling west with a velocity of 414 meters per second and a wavelength of 1.8 meters? hertz

LuckyWell [14K]

Answer:

230hz

Explanation:

Hello,

To solve this question, we gave to use the relationship between velocity-frequency-wavelength to find the frequency in this question.

V = Fλ

V = velocity or speed of the wave

F = frequency of the wave

λ = wavelength of the wave

Data;

V = 414m/s

λ = 1.8m

f = ?

V = fλ

f = v/λ

f = 414/1.8

f = 230hz

The frequency of the wave is 230hz

7 0

3 years ago

5.00 mol of ammonia are introduced into a 5.00 L reactor vessel in which it partially dissociates at high temperatures. 2NH 3(g)

allochka39001 [22]

Explanation:

system at equilibrium, will the reaction shift towards reactants ~

--?'

2. (2 Pts) Consider the reaction N2(g) + 3H2(g) =; 2NH3(g). The production of ammonia is an

exothermic reaction. Will heating the equilibrium system increase o~e amount of

ammonia produced? . .co:(

3. (2 Pts) Consider the reaction N2(g) + 3H2(g) =; 2NH3(g). Ifwe use a catalyst, which way will

the reaction shift? ':'\

.1.+- w~t s~,H (o')l r'eo.c. e~ ei~i"liht-,·u.fn\ P~~,

4. (3 Pts) ff 1ven th e o £ 11 owmg d t a a £ or th ere action: A(g) + 2B(s) =; AB2(g)

Temperature (K) Kc

300 1.5x104

600 55 k ' pr, cl l<..J~

e- ~ r fee, ct o. ~ 1<

900 3.4 X 10-3

Is the reaction endothermic or exothermic (explain your answer)?

t d- IS o.,;r-. \4\a..i~1f't~ °the te.Y'il(lf1,:J'u.r-a a•~S. j lrvdu..c,,.) +~H~to{' '\

exothe-rnh't.-- ,.. ..,. (/.., ,~.

5. (4 Pts) Consider the reaction, N2(g) + 3H2(g) =; 2NH3(g). Kc= 4.2 at 600 K.

What is the value of Kc for 4 NH3(g) =; 2N2(g) + 6H2(g)

N ... ~l + 3 H~(ri ~ ~Nli3~) kl,= ~:s;H,J3 # 4. J..

~ ;)N~~) ~ ~ H ~) ~\-_ == [A!;J:t D~~Jb

J. [,v 1+3] ~

I

4,:i.~ = 0,05

4 0

4 years ago

The mass of a deuterium nucleus 21H is less than its components masses. Calculate the mass defect.________ amu

Inessa [10]

Answer:

The mass defect of a deuterium nucleus is 0.001848 amu.

Explanation:

The deuterium is:

$^{A}_{Z}X \rightarrow ^{2}_{1}H$

The mass defect can be calculated by using the following equation:

$\Delta m = [Zm_{p} + (A - Z)m_{n}] - m_{a}$

Where:

Z: is the number of protons = 1

A: is the mass number = 2

$m_{p}$ : is the proton's mass = 1.00728 amu

$m_{n}$ : is the neutron's mass = 1.00867 amu

$m_{a}$ : is the mass of deuterium = 2.01410178 amu

Then, the mass defect is:

$\Delta m = [1.00728 amu + (2- 1)1.00867 amu] - 2.01410178 amu = 0.001848 amu$

Therefore, the mass defect of a deuterium nucleus is 0.001848 amu.

I hope it helps you!

5 0

3 years ago

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